I am trying to make a collection of books that are just from reformed guys (Sproul, MacArthur, etc) and I cannot seem to find the right "rule". I tried doing "author:Sproul AND author: MacArthur, but as soon as I enter the AND everything went to zero results. It would be time consuming to build a collection based on aurthos, but if that is the only way I will just have to do it, but what did I do wrong in the "rule" above or is these an easier way to do it. Thank you for your help.