APA

Elzinga C. L., Salzer D. W. & Willoughby J. W. (1998). Measuring & monitoring plant populations. [Denver, Colo.]: U.S. Dept. of the Interior, Bureau of Land Management.

Chicago

Elzinga Caryl L, Salzer Daniel W and Willoughby John W. 1998. Measuring & monitoring plant populations. [Denver, Colo.]: U.S. Dept. of the Interior, Bureau of Land Management.

Harvard

Elzinga C. L., Salzer D. W. and Willoughby J. W. (1998). Measuring & monitoring plant populations. [Denver, Colo.]: U.S. Dept. of the Interior, Bureau of Land Management.

MLA

Elzinga Caryl L, Salzer Daniel W and Willoughby John W. Measuring & monitoring plant populations. [Denver, Colo.]: U.S. Dept. of the Interior, Bureau of Land Management. 1998.