(1995). Environment some focal issues. BSMS.
Chicago Style (17th ed.) ZitazioaEnvironment Some Focal Issues. Dehra Dun: BSMS, 1995.
MLA (9th ed.) ZitazioaEnvironment Some Focal Issues. BSMS, 1995.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.