Use VPN from your home/dormitory!
http://www.ff.cuni.cz/home/life-in-prague/it/vpn/
Legal (first three are substitutes if I get it correctly):
http://metalib.cuni.cz/
http://pez.cuni.cz/index.php?lang=en
ukaz.cuni.cz
https://scholar-google-com.ezproxy.is.cuni.cz/
https://books.google.com
bit.ly/1QmNlyU (centr. catalogue of Charles University)
http://www.soc.cas.cz/knihovna/katalog (library of Sociological Institute of Czech Academy of Sciences) (click on "katalog knihovny" and then switch to English)
http://www.nkp.cz/ (Czech National Library)
Illegal:
http://gen.lib.rus.ec/ (scanned scientific books)
http://freescienceengineering.library.elibgen.org/
Halfway:
http://www.freefullpdf.com/#gsc.tab=0