APA

Guthrie D. M., .Polymorphism in the surface water bugs (Hemipt.-Heteropt: Gerroidea). : .

Chicago

Guthrie D M, .Polymorphism in the surface water bugs (Hemipt.-Heteropt: Gerroidea). : .

Harvard

Guthrie D. M., .Polymorphism in the surface water bugs (Hemipt.-Heteropt: Gerroidea). : .

MLA

Guthrie D M, .: . .