Ryan, W. J. L. (1958). Price theory. Macmillan; St. Martin's Press.
Chicago Style (17th ed.) ZitazioaRyan, William James Louden. Price Theory. London, New York: Macmillan; St. Martin's Press, 1958.
MLA (9th ed.) ZitazioaRyan, William James Louden. Price Theory. Macmillan; St. Martin's Press, 1958.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.