Paying for bmj.com: is this measure scientific literature's half open sesame?
Tam
Clarence C
CC
Lopman
Ben A
BA
Handan
Dina
D
D005249:Fees and Charges; D033181:Information Dissemination; D020407:Internet / Q000600:supply & distribution; D010506:Periodicals as Topic / Q000191:economics / Q000600:supply & distribution*; D006113:United Kingdom