Ancient common moxibustion monographs are:
Moxibustion secret biography
Emergency moxibustion preparation method
Shenjiu economy
Ai Cai bianyi
You must have a strong knowledge of classical Chinese to read these medical books, otherwise it will look very difficult. If your classical Chinese is poor, you can look at the vernacular annotated editions of these books. For example, the secret biography of moxibustion is now annotated in vernacular Chinese. For books about modern moxibustion, please read the selected readings of Moxibustion Essence and Moxibustion in Xie Xiliang.