Johnson และผู้แต่งคนอื่นๆ. 2001. The nutritional implications of deforestation : how ecological change in affecting the availability of wild planls as beta-carotene sources : a study of two Karen communities of northern Thailand. Faculty of Agriculture, Faculty of Agriculture Chiang Mai University;
Johnson และผู้แต่งคนอื่นๆ. (2001) The nutritional implications of deforestation : how ecological change in affecting the availability of wild planls as beta-carotene sources : a study of two Karen communities of northern Thailand . Faculty of Agriculture Chiang Mai University/Chiang Mai.
Johnson และผู้แต่งคนอื่นๆ. The nutritional implications of deforestation : how ecological change in affecting the availability of wild planls as beta-carotene sources : a study of two Karen communities of northern Thailand. . Chiang Mai:Faculty of Agriculture Chiang Mai University, 2001.
Johnson และผู้แต่งคนอื่นๆ. (2001) The nutritional implications of deforestation : how ecological change in affecting the availability of wild planls as beta-carotene sources : a study of two Karen communities of northern Thailand . Faculty of Agriculture Chiang Mai University/Chiang Mai.