The asters of Ontario :
Aster L. and Virgulus Raf. (Compositae : Astereae) /
by John C. Semple and Stephen B. Heard.

APA Citation

Semple, J. C., Heard, S. B. (1987). The asters of Ontario: Aster L. and Virgulus Raf. (Compositae : Astereae). Waterloo, Ont.: Dept.of Biology, University of Waterloo.

MLA Citation

Semple, John C, and Stephen B Heard. The Asters of Ontario: Aster L. And Virgulus Raf. (Compositae : Astereae). Waterloo, Ont.: Dept.of Biology, University of Waterloo, 1987.

Warning: These citations may not always be complete (especially for serials).