https://protege.stanford.edu/about.php has this text:
A WORD ABOUT CITING
We would be grateful if scientific publications resulting from projects that make use of Protégé would include the following sentence in the acknowledgments section:
“This work was conducted using the Protégé resource, which is supported by grant GM10331601 from the National Institute of General Medical Sciences of the United States National Institutes of Health.”
Please use the following reference citation for Protégé:
Musen, M.A. The Protégé project: A look back and a look forward. AI Matters. Association of Computing Machinery Specific Interest Group in Artificial Intelligence, 1(4), June 2015. DOI: 10.1145/2557001.25757003.
There is also a link to PMC in the title of that. I'm not sure if it's reasonable to try to infer that this DOI is the requested citation.
https://protege.stanford.edu/about.php has this text:
There is also a link to PMC in the title of that. I'm not sure if it's reasonable to try to infer that this DOI is the requested citation.