Scheel, R. L. (1987). Introduction to the future. ETC Publications.
Chicagoスタイル(17版)引用形式Scheel, Randall L. Introduction to the Future. Palm Springs, Calif.: ETC Publications, 1987.
MLA(9版)引用形式Scheel, Randall L. Introduction to the Future. ETC Publications, 1987.
警告: この引用は必ずしも正確ではありません.