Anderson, L. E., H. A. Crum & W. R. Buck 1990. List of mosses of North America north of Mexico. Bryologist 93: 448–499.
Ando, H. 1972. Distribution and speciation in the genus Hypnum in the circum-Pacific region. J. Hattori Bot. Lab. 35: 68–98.
Ando, H. 1997. A new subspecies of Hypnum callichroum from Japan, with a preliminary list of the species of Hypnum sect. Hamulosa and their distribution. J. Hattori Bot. Lab. 82: 19–25.