@article {38668,
	title = {An index of site productivity for uneven-aged or mixed-species stands},
	volume = {23},
	year = {1993},
	pages = {558-562},
	publisher = {Canadian Journal of Forest Research},
	url = {http://article.pubs.nrc-cnrc.gc.ca/RPAS/rpv?hm=HInit\&calyLang=eng\&journal=cjfr\&volume=23\&afpf=x93-074.pdf},
	author = {Huang, S. M. and Titus, S. J.}
}
