O'Brien, R. A., & Collins, D. C. (1991). Forest statistics for land outside national forests in West-Central Montana, 1989. Intermountain Research Station.
Cita Chicago (17th ed.)O'Brien, Renee A., i Dennis C. Collins. Forest Statistics for Land Outside National Forests in West-Central Montana, 1989. Ogden: Intermountain Research Station, 1991.
Cita MLA (9th ed.)O'Brien, Renee A., i Dennis C. Collins. Forest Statistics for Land Outside National Forests in West-Central Montana, 1989. Intermountain Research Station, 1991.
Atenció: Aquestes cites poden no estar 100% correctes.