Preston, R. J. (1961). North American trees (2nd ed.). Iowa State University press.
シカゴスタイル引用形Preston, Richard J. North American Trees. 2nd ed. Iowa: Iowa State University press, 1961.
MLA引用形式Preston, Richard J. North American Trees. 2nd ed. Iowa State University press, 1961.
警告: この引用は必ずしも正確ではありません.