Hi, so I am a beginner and Intermediate level chess teacher here so I found a Susan Polgar book that I liked and wish to add to my curriculum as an Independent teacher till what extend can I use the material the puzzles legally

Would appreciate your help on the front page it is written something like legally you aren't allowed to... something something which is written on every such book

Thanks in Advance

Please note this is my first time working independently and wish to be ethical