Quellen für wissenschaftliche Literatur (alle Themen)

Most of the time you will need to be in a university network or use a VPN to be able to access articles online. But often you will also find free article versions (PDFs) on the Web (e.g., on ResearchGate).

http://scholar.google.com/
https://www.researchgate.net/
http://portal.acm.org/dl.cfm
http://www.sciencedirect.com/
http://www.computer.org/portal/web/search/advanced
http://link.springer.com
http://www.jstor.org
http://www.emeraldinsight.com
http://search.proquest.com/
http://aisel.aisnet.org
https://www.springerprofessional.de

Conference Proceedings:
IEEE, ACM ...
ICIS: http://aisel.aisnet.org/icis/
AMCIS: http://aisel.aisnet.org/amcis/
ECIS: http://aisel.aisnet.org/ecis/

Springer Lecture Notes in Computer Science (LNCS) (via SpringerLink)

Also many different specialized conferences by ACM, IEEE ... (via ACM / IEEE Digital Libraries)

Wirtschaftsinformatik / BISE
http://www.bise-journal.com
https://www.springerprofessional.de/wirtschaftsinformatik/3421682