APA

Claassen P. W., . (1931). Plecoptera nymphs of America (north of Mexico). Springfield, Ill: Pub. for the Thomas Say Foundation by C. C. Thomas.

Chicago

Claassen Peter Walter, . 1931. Plecoptera nymphs of America (north of Mexico). Springfield, Ill: Pub. for the Thomas Say Foundation by C. C. Thomas.

Harvard

Claassen P. W., . (1931). Plecoptera nymphs of America (north of Mexico). Springfield, Ill: Pub. for the Thomas Say Foundation by C. C. Thomas.

MLA

Claassen Peter Walter, . Plecoptera nymphs of America (north of Mexico). Springfield, Ill: Pub. for the Thomas Say Foundation by C. C. Thomas. 1931.