Ryan, W. J. L. (1958). Price theory. Macmillan; St. Martin's Press.
Chicago-čujuhus (17. p.)Ryan, William James Louden. Price Theory. London, New York: Macmillan; St. Martin's Press, 1958.
MLA-čujuhus (9. p.)Ryan, William James Louden. Price Theory. Macmillan; St. Martin's Press, 1958.
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