As for children's massage, I suggest you read Li's book, because it is Mr. Li of Qingdao Hospital of Traditional Chinese Medicine who really carries forward the three-character classic of massage.
Chen Yuqin, an expert in TCM health care, is the founder of "Meridian and Acupoint Massage Therapy". She is a unique master of folk Chinese medicine who started from treating herself and has vivid experience. His thought, theory and practice have also been affirmed and respected by many famous doctors in China, which has had a lot of great influence. To some extent, Wu Qingzhong, the author of Manual for Human Use, is from Chen Yuqin.
You can read all these books. If you want to study systematically, you can look at the theory of zang-fu organs in traditional Chinese medicine and so on.