Here are some articles about student retention, textbook costs, and library efforts to increase student retention by championing affordable learning and open education resources (OER).
Croteau, E. (2017). Measures of Student Success with Textbook Transformations: The Affordable Learning Georgia Initiative. Open Praxis, 9(1), 93–108.
Hilton III, J., & Laman, C. (2012). One college’s use of an open psychology textbook. Open Learning, 27(3), 265–272
Holderman, S., & Primary Research Group. (2019). Profiles of Academic Library Efforts to Enhance Student Retention. Primary Research Group Inc.
Salem, J.A., Jr. Open Pathways to Student Success: Academic Library Partnerships for Open Educational Resource and Affordable Course Content Creation and Adoption. The Journal of Academic Librarianship, 43 (1), 34-38.
Valentino, M. and Hopkins, G. (2020), No textbook cost general education pathway: an effort to increase retention at Central Washington University, Reference Services Review, Vol. 48 No. 3, pp. 503-522
Williams, L. (2013). Textbooks on Reserve. University Business, 16(4), 14.
Winitzky-Stephens, J., & Pickavance, J. (2017). Open Educational Resources and Student Course Outcomes: A Multilevel Analysis. International Review of Research in Open and Distributed Learning, 18(4), 35–49