1. Kortemeyer, G.: Ten years later: why open educational resources have not noticeably affected higher education, and why we should care. EDUCAUSE Review Online, 02/26 (2013)
2. Gonçalves, M.A., Moreira, B.L., Fox, E.A., Watson, L.T.: What is a good digital library? A quality model for digital libraries. Inf. Process. Manag. 43, 1416 (2007)
3. Fuhr, N., Hansen, P., Mabe, M., Micsik, A., Soølvberg, I.: Digital libraries: a generic classification and evaluation scheme. In: Constantopoulos, P., Sølvberg, I. (eds.) Proceedings of ECDL ’01. Darmstadt, Germany (2001). 187
4. Xie, H.I.: Users evaluation of digital libraries (DLs): their uses, their criteria, and their assessment. Inf. Process. Manag. 44, 1346 (2008)
5. Borgman, C.L., Gilliland-Swetland, A.J., Leazm, G.H., Maym, R., Gwynn, D., Gazan, R., Mautone, P.: Evaluating digital libraries for teaching and learning in undergraduate education: a case study of the Alexandria Digital Earth Prototype (ADEPT). Libr. Trends 49, 221 (2000)