APA

Hoffman F. M., .Fixed-wing airplane versus helicopter surveys of manatees (<Trichechus manatus>). : .

Chicago

Hoffman Forrest M, .Fixed-wing airplane versus helicopter surveys of manatees (<Trichechus manatus>). : .

Harvard

Hoffman F. M., .Fixed-wing airplane versus helicopter surveys of manatees (<Trichechus manatus>). : .

MLA

Hoffman Forrest M, .: . .