Before going up the hill to the syrup witch's house, there is an entrance at the lower right, which can be opened with digging gloves. After entering, you come to Mayor Hagen's lake house. There is a big tree outside the hut. After sprinting into a shrinking array, enter the room from the back of the hut, cross the pool, push the bookshelf to the right (provided that you have got the power ring before, you can push things even if you shrink), then go to the fireplace and push the book down. After collecting all three books, I went to the upper left shelf on the second floor of the library. I chatted with my elders and suddenly fell into a cave with flippers. Now I can swim to the next element maze.