For PhD students and postdocs

Find the paper you missed before your referee does.

Paste your abstract and reference list. About ten minutes later you'll know whether your main claim is already published, which papers a referee will expect you to cite, and whether any of your references have problems.

Why I built it

My dissertation topic turned out to have more or less been done before. I spent months finding the papers. Other researchers have told me they found out from a referee, which is worse.

It usually isn't that anyone was careless. Climate science borrows from oceanography, ecology, hydrology and atmospheric physics, and each field names things its own way. In the 438,284 papers we hold, nobody writes "marine heatwave" before 2016. By 2019 it's the main term. The events are older than the name (how we counted), and you can't search for a word you don't know.

What you get

Before your check runs, I add the papers that cite the same sources you do. That's usually where the missed paper is. Then you get three answers:

  • Is my main claim already published? Claimed gives you the paper that already makes it. Adjacent says what the nearest work did and where yours differs. Open means we didn't find it, which tells you about our corpus, not proof nobody has done it.
  • What am I missing? Papers a referee will expect you to cite that aren't in your list, each with why it matters and how yours differs.
  • Is my reference list clean? Retracted papers, corrections, preprints that have since been published, and years or DOIs that don't match.

The first check is free and shows you the headline results. The full check is $19 a paper, and you can re-check it for 30 days as you edit.

Real results

Unedited results from the engine behind the check, on ideas I wrote for this page. Every paper is real and each title links to it.

Terminal · a claim already maderun 19 October 2026
Idea in

Marine heatwaves have become longer and more frequent across the global ocean over the past century.

Already claimedgrounding verified

read as: Marine heatwaves have become longer and more frequent across the global ocean over the past century.

Eric C. J. Oliver et al. · 2018 · Nature Communications

Using a range of ocean temperature data including global records... we identify significant increases in marine heatwaves over the past century. We find that from 1925 to 2016, global average marine heatwave frequency and duration increased by 34% and 17%, respectively...

Claimed, with the paper that already makes the claim and the passage where it does. The same result also listed seven adjacent studies of shorter records or single regions, left out here to keep it short.

Terminal · a clear deltarun 19 October 2026
Idea in

A ten-year in-situ seasonal time series shows pteropod shell dissolution increases each winter in the California Current.

Adjacent · a clear deltagrounding verified

read as: Pteropod shell dissolution increases each winter in the California Current

Bednaršek2014 established a strong correlation between severe shell dissolution and undersaturated waters in the California Current Ecosystem, but did not determine if this dissolution follows a specific annual winter cycle. Your contribution is therefore identifying that shell dissolution increases each winter, adding critical temporal resolution to the known spatial and long-term trends.

Lisette Mekkes et al. · 2021 · Scientific Reports

established: Pteropods in the California Current Ecosystem make thinner shells along the upwelling gradient from offshore to nearshore due to reduced calcification rather than dissolution.

did not: Demonstrate that shell dissolution increases specifically during winter or establish a seasonal pattern of dissolution intensity.

your delta: Establishing a seasonal (winter) increase in shell dissolution rates in the California Current, distinguishing temporal variability from the spatial gradients and calcification mechanisms previously identified.

Nina Bednaršek et al. · 2014 · Proceedings of the Royal Society B Biological Sciences

established: A strong correlation exists between severe shell dissolution damage and undersaturated water in the top 100m of the California Current Ecosystem, with incidence doubling since pre-industrial times.

did not: Determine if this dissolution follows a specific annual winter cycle or if it is constant throughout the year.

your delta: Confirming a specific seasonal pattern where dissolution peaks each winter, refining the baseline understanding of habitat suitability decline.

Adjacent. The engine found five close papers, none of which tested for a winter peak, and its delta line says where the idea would add to them. Two of the five are shown. The idea mentioned a ten-year time series; the claim it checked is the "read as" line.

Terminal · the same idea in other wordsrun 19 October 2026
Idea in

Narrow corridors of intense water vapour transport from the tropics cause most extreme winter rainfall on the US West Coast.

Prior work
Ju‐Mee Ryoo et al. · 2015 · Journal of Geophysical Research Atmospheres

The idea never says "atmospheric river". Four of the first six papers in the prior-work list have the phrase in their title, because that is the field's name for these corridors. These are the first six of thirteen. The verdict on this wording was Adjacent.

Where it works, and where it doesn't

We hold about half of the last ten years of papers on ice and snow, permafrost, tropical cyclones, ozone and ocean acidification. On hydrology, floods, wildfire and marine biology it's fewer than one in twenty before a check, so the papers added for your check matter more there. Every result says how much of your reference list we hold.

Strongest areas
  • Arctic and Antarctic ice59%
  • Tropical and extratropical cyclones54%
  • Ozone and climate52%
  • Snow, ice and glaciers50%
  • Ocean acidification48%
  • Permafrost43%
Weakest areas
  • Hydrology and drought4%
  • Marine biology3%
  • Palaeoclimate and geology2%
  • Plant water and carbon2%
  • Flood risk1%
  • Wildfire1%

The share of each area's papers from the last ten years that we hold, measured on 13 October 2026 against a random sample from OpenAlex. Each figure is a few points either way.

Questions

Why not just use Google Scholar, or ask my supervisor?

Keep doing both. Scholar finds what you know to ask for, and your supervisor knows their corner well. This is for the gap between them: a neighbouring field, or a paper from fifteen years ago written in words you wouldn't search. Every paper links to its source, so you can check it in a minute.

Why do you need my reference list?

So you only see what you're missing, and so I can add the papers that cite the same sources you do before the check runs.

Does it cover my field?

If you work in climate or earth science, probably. It isn't built for biomedicine or chemistry, and when coverage of your topic is thin it says so.

Can it be wrong?

Yes. It can miss a paper, and it can flag one that turns out to be less related than it looked. That's why it shows its reasoning for every paper instead of a bare score, and you stay the judge. If a paper should have shown up, tell me with the buttons under the result. I trace each one back to where the search lost it, and every confirmed miss becomes a test the next version has to pass.

Is my paper safe?

Your paper is never published or shown to anyone else, and it isn't used to train models. To run the check, its text goes to our AI provider without your name or email. The privacy policy has the details.

What does it cost?

The first check is free, no card needed. The full check is $19 a paper, no subscription, and you get a full refund within 14 days if it wasn't useful. More on the pricing page.

Check your own paper

Run a free check

One free check per email address. No card needed.