Li Houlai's The Beauty of Numerology
Ying Si, a layman, "Eight Characters Leak"
Zhu Zuxia's Application of Numerology
Song Yingcheng's revelation of the eight-character truth
Li Hongcheng's Four-Pillar Destiny and Four-Pillar Ten Combinations 1000 Question and Answer.
Feng Huacheng's The Mystery of Numerology
The Four Pillars of Qu Wei's Truth
Most of the above books come from actual combat, and they have benefited a lot from reading them.