I am looking for decent resources to practice and learn Microeconomics. I need problems that are more involved unlike the ones in Varian's Workbook. For this, I decided to use Nicholson and Snyder (NS) and Lecture Notes by Ariel Rubinstein. The major issue with Rubinstein is that there's no solution manual. I found a similar course offered by Dirk Bergemann in 2012, and he in fact used the book by NS. Here's the course: https://campuspress.yale.edu/dirkbergemann/teaching/econ-121b-2012/.
If you know of a site, course or a (free e-) book that provides problems of at least a similar level, please let me know.