Well the book in particular that had a bit about weaning puppies was just a general training book not for yorkies specifically. I did also check out a The Life Of Yorkshire Terriers but not sure if that had anything to say about puppies as I haven't finished it. I got like 4 or 5 books from the library and haven't finished them all, just been reading tidbits from them.
I looked at some websites though, they say the same things about 3-4 weeks.
And I seen it on this forum here at yorkietalk
http://www.yorkietalk.com/forums/bre...soon-wean.html
If other people that have experience breeding and weaning puppies do this in 3 weeks or so, I don't see how 6 weeks is so bad..