If you are searching for papers or publications, here are some usefull
links:

- http://citeseer.nj.nec.com/cs
- http://www.sciencedirect.com
- http://www.acm.org/dl
- http://www.google.com

For psychology/perception papers:

- http://www.psycinfo.com/library/
- http://www.ncbi.nih.gov/entrez/query.fcgi