APA (7th ed.) Citation

Sonnichsen, C. L. (1968). Pass of the North: Four centuries on the Rio Grande. Texas Western Press.

Chicago Style (17th ed.) Citation

Sonnichsen, C. L. Pass of the North: Four Centuries on the Rio Grande. [El Paso]: Texas Western Press, 1968.

MLA (9th ed.) Citation

Sonnichsen, C. L. Pass of the North: Four Centuries on the Rio Grande. Texas Western Press, 1968.