Widén, C. (1991). The Phloroglucinols of Dryopteris villari complex and some related ferns Pteridophyta, Dryopteridaceae ([Sonderdr.].).
Chicago Style (17th ed.) CitationWidén, Carl-Johan. The Phloroglucinols of Dryopteris Villari Complex and Some Related Ferns Pteridophyta, Dryopteridaceae. [Sonderdr.]. 1991.
MLA (9th ed.) CitationWidén, Carl-Johan. The Phloroglucinols of Dryopteris Villari Complex and Some Related Ferns Pteridophyta, Dryopteridaceae. [Sonderdr.]. 1991.
Warning: These citations may not always be 100% accurate.