1. Trends and Gaps in Empirical Research on Open Educational Resources (OER): A Systematic Mapping of the Literature from 2015 to 2019. Issue 4 (2021) Authors: Otto, Daniel; Schroeder, Nadine; Diekmann, Daniel; Sander, Pia Journal: Contemporary educational technology Issue: Volume 13:Issue 4(2021) Page Start: Record Type: Journal Article View Content: Available online (eLD content is only available in our Reading Rooms) ↗