APA

St. John H., .Monograph of the genus Elodea (hydrocharitaceae) Part 3. The species found in Northern and Eastern South America. : .

Chicago

St. John H, .Monograph of the genus Elodea (hydrocharitaceae) Part 3. The species found in Northern and Eastern South America. : .

Harvard

St. John H., .Monograph of the genus Elodea (hydrocharitaceae) Part 3. The species found in Northern and Eastern South America. : .

MLA

St. John H, .: . .