OAIster is a union catalog of millions of records representing open access digital resources that was built by harvesting from open access collections worldwide.
OAPEN Library (Open Access Publishing in European Networks) is a collaborative initiative to develop and implement a sustainable Open Access publication model for academic books in the Humanities and Social Sciences.
OECD iLibrary Publications from the Organisation for Economic Co-operation and Development. It contains all the publications and datasets released by OECD.
Open Knowledge Repository - The World Bank is the largest single source of development knowledge. The World Bank Open Knowledge Repository (OKR) is The World Bank’s official open access repository for its research outputs and knowledge products.
