Widén, C. (1969). Chemotaxonomic investigations on Finnish Dryopteris species and related North American taxa ([Sonderdr.].).
Chicago Style (17th ed.) CitationWidén, Carl-Johan. Chemotaxonomic Investigations on Finnish Dryopteris Species and Related North American Taxa. [Sonderdr.]. 1969.
MLA (9th ed.) CitationWidén, Carl-Johan. Chemotaxonomic Investigations on Finnish Dryopteris Species and Related North American Taxa. [Sonderdr.]. 1969.
Warning: These citations may not always be 100% accurate.