Art and archaeology technical abstracts

Agora

ArXiv

Biodiversity Heritage Library - BHL

Biblioteca virtual

The British Library Main Catalogue

ChemSpider

Consultant

Dialnet

CISCO Networking Academy

Encyclopedia of Life - EOL

Eumed.net

Euclid Project

Epistemonikos

ERIC - Institute of Education Science

Global Biodiversity Information Facility - GBIF

ICT Statistics – ITU

IMSLP-Petrucci Music Library

Instituto de Ciencias Naturales

Master Muscle List

OECD iLibrary

Openverse

Pedro: Physiotherapy Evidence Database

Pub Med

REDIB

Springer Link

Trade Map

UNESCO Digital Library

World bank open data

WorldWide Science