Walker, B. (1909). Notes on Planorbis II: P. bicarinatus. The Nautilus, 23(1): 1-10, plate 1. page(s): 9 [details]
MolluscaBase (2019). MolluscaBase. Planorbis bicarinatus var. royalensis B. Walker, 1909. Accessed at: http://www.molluscabase.org/aphia.php?p=taxdetails&id=1354267 on 2021-01-15