Grierson, A. J. C. Flora of Bhutan : including a record of plants from Sikkim and Darjeeling / A.J.C. Grierson & D.G. Long - Edinburgh : Royal Botanic Garden, 1999. - v.2, part.2 ; 427-1033 p. illustrations; 20 cm. ISBN: 1872291430 Dewey Class. No.: 582.13095498 GRI