De Souto, M. S. (1985). Group travel operations manual. Delamr Pub.
Chicagoスタイル(17版)引用形式De Souto, Martha Sarbey. Group Travel Operations Manual. Albany, N.Y: Delamr Pub, 1985.
MLA(9版)引用形式De Souto, Martha Sarbey. Group Travel Operations Manual. Delamr Pub, 1985.
警告: この引用は必ずしも正確ではありません.