{{TurningpageNWFP |title=Coppen, ''Gums, resins and latexes of plant origin'', 1995 |titlepreviouspage=Peru and Tolu balsams (FAO, NWFP 6)|previousshortname=Peru and Tolu balsams|titlefollowingpage=Elemi (FAO, NWFP 6)|followingshortname=Elemi}} *See the main page [[:fr:CopalBaumes|CopalBaumes]] (in French)
*Extract from : NWFP 6. Coppen J.J.W., 1995. ''Gums, resins and latexes of plant origin''. FAO, Rome. 142 p. (''Non-Wood Forest Products'', '''6'''). [http://www.fao.org/home/search/en/?q=Gums%2C%20resins%20and%20latexes on line]