Cita APA (7th ed.)

Allen, C. F. 1., & Allen, C. f. 1. (1959). Railroad curves and earthwork (7th ed.). McGraw-Hill.

Cita Chicago (17th ed.)

Allen, Calvin Francis 1851, i Calvin francis 1851 Allen. Railroad Curves and Earthwork. 7th ed. New York: McGraw-Hill, 1959.

Cita MLA (9th ed.)

Allen, Calvin Francis 1851, i Calvin francis 1851 Allen. Railroad Curves and Earthwork. 7th ed. McGraw-Hill, 1959.