I was watching the dedicated reading season 3. I finished lecture 1(main idea), 2(sentence simplification) and 3(practice). I feel that to improve those skills I will have to do a lot of untimed practice. I can practice the reading passages from the gre bigbook and official guides. But I want to save those problems for timed practice. For this reason, I am looking for other resources, where I can practice as many passages as I want, to improve those skills. Are there any available resources other than bigbook and official guides?
The big book has a lot of tests, why not do one timed and one untimed from each test as suggested in the study plans?