[http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFD-47WD89K-6&_user=10&_coverDate=06%2F01%2F2003&_alid=467430042&_rdoc=3&_fmt=summary&_orig=search&_cdi=5224&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=ed9d7ea0f98ad90eddd946d7478fc693]* Lee, Yin-Tse & Langenheim, Jean H. (1975).
[http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFD-47WD89K-6&_user=10&_coverDate=06%2F01%2F2003&_alid=467430042&_rdoc=3&_fmt=summary&_orig=search&_cdi=5224&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=ed9d7ea0f98ad90eddd946d7478fc693]* Lee, Yin-Tse & Langenheim, Jean H. (1975).