Cita APA

Krebs, R. D., & Walker, R. D. (1971). Highway materials. McGraw-Hill.

Citación estilo Chicago

Krebs, Robert D., and Richard D. Walker. Highway Materials. New York: McGraw-Hill, 1971.

Cita MLA

Krebs, Robert D., and Richard D. Walker. Highway Materials. New York: McGraw-Hill, 1971.