Max RAM for MacBook Pro 13-inch, Early 2011?

I have a 13-inch MacBook Pro (early 2011 model). The Apple page for that particular machine seems to say that the max RAM is:

4GB (two 2GB SO-DIMMs) of 1333MHz DDR3 memory; two SO-DIMM slots support up to 8GB

However, when I found the same model MBP on Crucial, the reccommended upgrade suggested was a 16GB kit (2 x 8GB SO-DIMMs).

Does anybody know which one of these suggestions is right? I obviously don't want to buy double the RAM that I need, but at this point I would quite like to max it out....??