Welfling, Weldon . Principles of Economics / Textual Documents Weldon Welfling. - 1st ed. / - New York : McGraw - Hill book company , 1971. - vii,488p. : ill ; 24cm . - Part I- Index ISBN: 07-069185-1 Subjects--Index Terms: Economics G-Economics Market Economy Dewey Class. No.: 330 / W 457 P