anyone know of any GOOD informative sites on aging deer by teeth?? pics...threads...reading...

anyone consider themselves good/knowledgable/expert etc at it??

i found a couple sites online...i still dont think i fully understand it...and i know each deer and tooth will vary so its nothing VERY concrete....just looking to do a little reading on the subject...if anyone considers themselves knowledgeable on the subject and wants to help me out, id appreciate that too..