I work at Concordia University St. Paul in the library. One of my colleagues found an open source pressbook textbook that one of our faculty would like to use in her class: https://traumainformedschoolpractices.pressbooks.com/
I noticed that there is a MARC metadata record available for this work which one can get though oclc (you can see it displaying data here: http://www.worldcat.org/oclc/1124766881).
I am wondering if there is one place where I might be able to locate a file of Pressbooks MARC records like this for other OER textbooks (much like what is offered from eBooks Minnesota). Or if this might be planned for the future…