At some point, my kids had mastered the first Set of BOB books. We moved on to the second set of BOB books, following the same approach. After that, my kids split in their next step. One child read the third Set of BOB books. The other was getting antsy with the little books and wanted to read a “real” book. So, we switched series. I bought a set of Modern Curriculum Press – Phonics Practice Readers and we started reading those sets. These books are a bit larger than the BOB books, but still a real phonics approach, progressively more difficult, with engaging pictures and stories that I remember 35 years after learning to read with them. The books were a step back in difficulty after reading the second Set of BOB books, which was a boost to the kids’ confidence. But they have longer sentences and more words per book, so they helped build the kids’ reading stamina. The books are out of print, but I have not found a set of phonics readers that I like as much, as a perfect step after the BOB books. I bought our set on ebay.