wood rosin glycerol ester of wood rosin English 英語版 ester gum wood rosin Wikipedia 英語版 Wikipedia calls it glycerol ester of wood rosin glycerol ester of wood rosin wood rosin glycerol ester of wood rosin glycerol ester of wood rosin glycerol ester of wood rosin http://en.wikipedia.org/wiki/Glycerol_ester_of_wood_rosin glycerol ester of wood rosin glycerol ester of wood rosin glycerol ester of wood rosin glycerol ester of wood rosin ester of wood rosin glycerol ester of wood rosin glycerol ester of wood rosin ester of wood rosin glycerol ester of wood rosin ester gum