Try www.kubotabooks.com, depending on the tractor you can get all three. Work shop, parts and owners. Www.kubota.servicemanualvault.com has work shop manuals for 10$. If it's a newer tractor you may have to bite the bullet and go thru messicks or goldeneagledirect.
I have used service manual vault twice. When I downloaded the manual, I got the wrong one both times. I e-mailed them the second time and haven't gotten a response. Maybe I need to check my spam folder.
There is one for some of the older L's that is not on that list because it is larger than he can host. I tried sending it to him and he said he can't host it. There is a link to it in another thread here.
If your looking for a manual for a L3010, sorry no luck on a free or cheap one to be had.
Its just one of those that hasn't gotten scanned and put out there yet.