Researcher ID
Researcher ID is a global, multi-disciplinary scholarly research community. Each researcher listed is assigned a unique identifier, to aid in solving the common problem of author misidentification. Search the registry to find citations, collaborators, and more.

ICTP Open Access Archive for e-Prints
- Physical, Mathematical, Biological, Earth, Computer and Engineering Sciences
The ICTP Open Access Archive of the Science Dissemination Unit allows scientists from anywhere to post on-line, at no cost, their scientific work and scientific CV in electronic format

NSDL National Sciences Digital Library
- The comprehensive source for science, technology, engineering and mathematics education. Funded by the National Science Foundation

Ingenta Connect
- The home of scholarly research
IngentaConnect offers one of the most comprehensive collections of academic and professional research articles online.

Ei Engineering Information
- is the leader in providing online information, knowledge and support of the highest professional relevance for research and industrial practitioners in applied physical sciences and engineering.

CIRS - International reference of scientific web sites

WolframAlpha
- Computational knowledge engine
WolframAlpha is the first step in an ambitious, long-term project to make all systematic knowledge immediately computable by anyone

PEERS service of IoP
- PEERS is a FREE service from Institute of Physics Publishing. It provides a moderated global e-mail directory of people working in science.

Google Advanced Scholar Search