Actually both books, but I was particularly thinking first of the "Aha Insight!" book, which has like 100 different problems where some clever thinking/turning

Actually both books, but I was particularly thinking first of the "Aha Insight!" book, which has like 100 different problems where some clever thinking/turning around the problem statement helps to solve it. The other one ("Aha Gotcha"), you are right is more about paradoxes that arise when applying logic that seems to lead to contradictory outcomes. But it also has a lot of "change the way of thinking" answers.