3 literature references for Lophophora williamsii (Lem. ex Salm-Dyck) J.M. Coult.:

Author:
Year: 2011
Title:
Source: Checklist of CITES Species Part 1 CITES species index
Author:
Year: 2000
Title:
Source: database, The PLANTS Database
Author:
Year: 1996
Title:
Source: database, The PLANTS Database