APA

Yapp M. T., Steward J. & Whitcomb W. G. (1991). Existing methods for the structural design of aggregate road surfaces on forest roads. : Transportation Research Record.

Chicago

Yapp Margot TY, Steward John and Whitcomb William G. 1991. Existing methods for the structural design of aggregate road surfaces on forest roads. : Transportation Research Record.

Harvard

Yapp M. T., Steward J. and Whitcomb W. G. (1991). Existing methods for the structural design of aggregate road surfaces on forest roads. : Transportation Research Record.

MLA

Yapp Margot TY, Steward John and Whitcomb William G. Existing methods for the structural design of aggregate road surfaces on forest roads. : Transportation Research Record. 1991.