Recommended: The Trilogy of Jiang Dahong's masterpiece Distinguishing the Meaning of Geography and the popular Shen Shi Metaphysics.
Star method can be found in Eye of the Earth, Bullet Shot and The Complete Book of Shafa (written by Zhang Jiuyi).
The three-in-one method can be found in five strategies of geography and geographical truth.
As for the classic works, it should be said that different people have different opinions. Most of the works left by sages of past dynasties are classics. If you really want to find it as a textual research, then the geographical works included in Siku Shushu Quanshu can be called classic works, right? But many feng shui masters I know, hehe, rarely read these classic works. They regard the books listed above as classics.
Of course, if you want to study geography, you must study these two books, a thorough explanation of the compass and a defense of the subject. But modern times pay attention to houses, so we should read books on houses such as Three Essentials of Houses.