Chellas, B. F. (1980). Modal Logic: An introduction. C. U. Pr..
Chicago Style (17th ed.) ZitazioaChellas, Brian F. Modal Logic: An Introduction. Cambridge: C. U. Pr., 1980.
MLA (9th ed.) ZitazioaChellas, Brian F. Modal Logic: An Introduction. C. U. Pr., 1980.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.