De, H.C.P. et al. 2011. Taxonomic Observations on the Genus Pyrrosia Mirbel from District Chamoli of Uttarakhand State (India). Indian Forester. 137, 9 (Sep. 2011), 1082–1088. DOI:https://doi.org/10.36808/if/2011/v137i9/12410.