For Lycopodium
Haines, A.A. 2003a. The families Huperziaceae and Lycopodiaceae of New England: a taxonomic and ecological reference. V.F. Thomas Co., Bowdoin, ME. 100 pp.
Haines, A.A. 2002b. Identification of Lycopodium lagopus. Botanical Notes 8: 4-5.
Hickey, R.J. 1977. The Lycopodium obscurum complex in North America. Amer. Fern J. 67: 45-48.
Øllgaard In Kramer, K.U., and P.S. Green. 1990. Pteridophytes and Gymnosperms. In K. Kubitzki, ed., The families and genera of vascular plants. Springer-Verlag, Berlin.
Øllgaard, B., and P.G. Windisch. 2014. Lycopodiaceae in Brazil. Conspectus of the family. I. The genera Lycopodium, Austrolycopodium, Diphasium, and Diphasiastrum. Rodriguésia 65: 293-309.
Rumsey, F.J. 2007. An overlooked boreal clubmoss Lycopodium lagopus (Laest. ex Hartm.) Zinserl. ex Kusen. (Lycopodiaceae) in Britain. Watsonia 26: 477-480.
Wagner, W.H., and J.M. Beitel. 1993. Lycopodiaceae. In Flora of North America Editorial Committee. 1993b. Flora of North America north of Mexico. Volume 2, pteridophytes and gymnosperms. Oxford Univ. Press, New York, NY. 475 pp.
Wagner, W.H., J.M. Beitel, and R.C. Moran. 1989. Lycopodium hickeyi: a new species of North American clubmoss. Amer. Fern J. 79: 119-121.
Zhang & Iwatsuki in FoC (2013)