Vol. 240, Issue 7, 1942July 01, 1942 EDT
Concretions of the Thomson Formation, Minnesota
Concretions of the Thomson Formation, Minnesota
George Melvin Schwartz,
Schwartz, G. M. (1942). Concretions of the Thomson Formation, Minnesota. American Journal of Science, 240(7), 491–499. https://doi.org/10.2475/ajs.240.7.491