Best references for less in demand sets/subsets?

DirtyHarry

Knowing there is only so much that can be listed in a SMR, Beckett or Tuff Stuff ----what other references are there (besides Ebay) for getting a handle on values? Or, can one assume that there really may be no value if not listed in one of these publications.

Caricon

One book I try to purchase every couple of year is the Sports Collectors Digest.
It's one of those hugh books that lists just about every card ever made, and lists
all those odd ball cards too like the 7-11 cards, cereal boxes, and many others.
Last time I bought one of those books, it was $40 but I really find it worth it
since it lists so much more then Beckett ever did.

One thing I would like Beckett to list again in there quartly issues is the
Pinnacle Mint with the coins. I still see many of the coins and cards all the
time at card shows, and that was one set I enjoyed collecting. I know
Beckett has to make room for new stuff to keep there magazine to so many
pages, but if I'm going to pay $10 for there big one every few months, it
should have everything listed that once was listed in there magazines.