APA (7th ed.) Citation

Heyl, A. V. (1959). The geology of the upper Mississippi Valley zinc-lead district. U.S. Govt. Print. Off.

Chicago Style (17th ed.) Citation

Heyl, Allen V. The Geology of the Upper Mississippi Valley Zinc-lead District. Washington: U.S. Govt. Print. Off, 1959.

MLA (9th ed.) Citation

Heyl, Allen V. The Geology of the Upper Mississippi Valley Zinc-lead District. U.S. Govt. Print. Off, 1959.