3 literature references for Orthotrichum laxifolium Wilson in Mitten, 1851:

Author: Crosby, M. R. and others - REVISED
Year: 1999
Title: REVISED: accepted in a monograph, revision, or descriptive flora since 1963
Source: Checklist Mosses
Author: Wilson in Mitten
Year: 1851
Title:
Source: Hooker's J. Bot. Kew Gard. Misc.
Author: Brotherus
Year: 1901
Title:
Source: Nat. Pflanzenfam.