APA

Halling R. E., .Notes on Collybia V. Gymnopus section Levipedes in tropical South America, wilth comments on Collibia. : .

Chicago

Halling Roy E, .Notes on Collybia V. Gymnopus section Levipedes in tropical South America, wilth comments on Collibia. : .

Harvard

Halling R. E., .Notes on Collybia V. Gymnopus section Levipedes in tropical South America, wilth comments on Collibia. : .

MLA

Halling Roy E, .: . .