Text ( visual ) : unmediated The development of a marketing planning model through simultaneous-equation multiple regression analysis : an airline study / by Randall L. Schultz. -- Ann Arbor, Mich. : University Microfilms , c1971. -- v, 202 leaves : ill. ; 21 cm. -- Bibliography: leaves 177-182 ; Facsim. reprint of the author's thesis(Ph.D.)--Northwestern University, 1970. -- (BA34357152) ; https://ci.nii.ac.jp/ncid/BA34357152 Author Heading(s): Schultz, Randall L.