DOAB Directory of Open Access Books
2017
DOAB Directory of Open Access Books
1995
DOAB Directory of Open Access Books
2012
DOAB Directory of Open Access Books
2021
DOAB Directory of Open Access Books
2016
DOAB Directory of Open Access Books
2020
DOAB Directory of Open Access Books
2010
OAPEN (Open Access Publishing in European Networks)
2020
DOAB Directory of Open Access Books
2020
Springer Nature Link eBooks - Fully Open Access
2020
OAPEN (Open Access Publishing in European Networks)
2019
DOAB Directory of Open Access Books
2019
Springer Nature Link eBooks - Fully Open Access
2019
ScienceDirect
1975