Preprints: The Basics: Citing Preprints
In Notice NOT-OD-17-050, the NIH provides a format example for citing preprints in publications:
Example: Bar DZ, Atkatsh K, Tavarez U, Erdos MR, Gruenbaum Y, Collins FS. Biotinylation by antibody recognition- A novel method for proximity labeling. BioRxiv 069187 [Preprint]. August 11, 2016 [cited 2017 Jan 12]. Available from: https://doi.org/10.1101/069187.
Preprint servers also give guidance for citing preprints. Here is an example from medRxiv:
Example: Author AN, Author BT. 2019. My article title. medRxiv doi: 10.1101/2019.12.11.12345678
If there are multiple versions of the preprint and you wish to cite a specific version, you can do so by adding the version-specific URL.
Example: doi: 10.1101/2019.12.11.12345678 version 2, https://www.medrxiv.org/content/10.1101/2019.12.11.12345678v2
Sources: National Institutes of Health [Internet]. Bethesda MD: National Institutes of Health; c2017. Reporting preprints and other interim research products; 2017 March 24; [about 3 screens]. Available from: https://grants.nih.gov/grants/guide/notice-files/NOT-OD-17-050.html
medRxiv [Internet]. Cold Spring Harbor NY: Cold Spring Harbor Laboratory; [date unknown]. Frequently asked questions (FAQ); [date unknown]; [about 3 screens]. Available from: https://www.medrxiv.org/about/FAQ