RE: Article on Japanese Woodblock Prints

Love Liman has a short article on this site pertaining to Japanese Woodblock Prints ( Article ), and in it he/she(?sorry?) states that:

"As a measurement of the necessary skill for carving, it can be mentioned that an apprenticeship of about ten years was required before a carver was considered to have mastered the craft."

I'm posting this thread to see if Love Liman them-self, or any other viewer for that matter, can tell me where they obtained this information? I tried all the reference links at the bottom of the article, but none of them seem to go into this kind of detail.
I've been trying for some time to research the training and lifestyle of the ukiyo-e block-carvers themselves (as opposed to the "artists") during the Edo period, but have only met repeated roadblocks, so whatever source this information came from could prove to be invaluable.
Thanks for your time all!

Lots of web resources, woodblock prints are complicated constructs often 1-4 people involved, old days yeah carver was long apprenticeship (maybe see artelino.com if I spelled that right) dependent on complexity one artists painting might require as many as 20 individual woodblock carvings, the printer had to be precise in overlaying one block coloring with the accumulating image. I own 4, my favorite artist is Tsuchiya Koitsu (1870-1949) who was on the cutting edge of the use of playing with lighting. my prize is his print "Benkei Bridge at Night". older prints such as this will have artists' signature and red seal "True", seal of publisher, and since the carver was so important seal of carver often found. Newer prints are on different paper and often the artist is expected to also be the carver (downsizing in the woodblock print world, sigh). hope that helped.