Clifton, R. T. F. (2015). Pelargonium section Otidia: Typification and verification notes for the published names P. laxum (Sweet) G. Don, P. keeromsberense, P. karooescens, P. hermansdorpense (= P. humansdorpense Clifford) ; diagnosis of the new name P. onustifolium (from P. 'Humansdorpense' Hort. / P. hermansdorpense auct.) and discussion of P. laxum sens. Vorster leading do segregation of the new species P. opinatum, P. opiparum, P. orientum. Group.
Chicago-Zitierstil (17. Ausg.)Clifton, Richard Timothy F. Pelargonium Section Otidia: Typification and Verification Notes for the Published Names P. Laxum (Sweet) G. Don, P. Keeromsberense, P. Karooescens, P. Hermansdorpense (= P. Humansdorpense Clifford) ; Diagnosis of the New Name P. Onustifolium (from P. 'Humansdorpense' Hort. / P. Hermansdorpense Auct.) and Discussion of P. Laxum Sens. Vorster Leading Do Segregation of the New Species P. Opinatum, P. Opiparum, P. Orientum. Dover: Group, 2015.
MLA-Zitierstil (9. Ausg.)Clifton, Richard Timothy F. Pelargonium Section Otidia: Typification and Verification Notes for the Published Names P. Laxum (Sweet) G. Don, P. Keeromsberense, P. Karooescens, P. Hermansdorpense (= P. Humansdorpense Clifford) ; Diagnosis of the New Name P. Onustifolium (from P. 'Humansdorpense' Hort. / P. Hermansdorpense Auct.) and Discussion of P. Laxum Sens. Vorster Leading Do Segregation of the New Species P. Opinatum, P. Opiparum, P. Orientum. Group, 2015.