Please click here for the Oxford and Pearson's ESS textbooks: https://drive.google.com/drive/folders/1o3yxqfWFPhZEcPMct3o_81JjFQ9fcpeb?usp=sharing
Oxford answers to questions from textbook: https://global.oup.com/education/secondary/curricula/ib-diploma/science/ess-answers/?region=international
A very useful book to read:
Thinking in Systems by Donella Meadows