ArXiv.org e-Print archive. Home | E-LIS. E-prints in Library and Information Science. DOAJ -- Directory of Open Access Journals. BioMed Central | The Open Access Publisher. Bioline International Official Site (site up-dated regularly) Accesso a la Investigacion Mundial en Linea en el Sector Agriculture. Pnud.com. OpenDOAR - Home Page - Directory of Open Access Repositories. Welcome to the Registry of Open Access Repositories - Registry of Open Access Repositories.
WorldCat: Redalyc. Red de Revistas Cientificas de América Latina y el Caribe, España y Portugal.