I'm trying to get some additional practice on stoichiometry, and was wondering if anyone can recommend any material? I have the TPR Science Workbook and Examkrackers GChem text, but the problems in these don't seem to be as difficult as the ones I encounter on the AAMC's. I was looking into ordering the Examkrackers 1001 Questions in Chemistry along with their Verbal workbook (which I've heard is quite good), but haven't seen too many good reviews on SDN about it. Any suggestions would be helpful, thanks!