Allen, George E. Report on short course on the control of the aquatic weeds and an assesment of their economic significance in Thailand - (s.l.) : International Plant Protection Center, 1977 - 96 p. ; mapas LCCN: 19088 Subjects--Topical Terms: Malas hierbas acuáticas--Control. Dewey Class. No.: 632.58 / A5