Mehm Tin Mon (2015). 《The Essence of Buddha Abhidhamma》. Third edition. Mehm Tay Zar Mon, Mya Mon Yadanar Literature. pp.38~39.
12 Division according to jāti (birth)
The cittas are divided into 4 classes according to jāti — viz.,
akusala, kusala, vipāka and kiriya cittas.
By looking at Chart No. 1, we can divide the 54 kāmāvacara cittas
into 12 akusala cittas, 8 kusala cittas, 23 vipāka cittas and 11 kiriya
cittas according to birth. The 23 vipāka cittas are collectively known
as kāma-vipāka cittas, and the 11 kiriya cittas are known as kāmakiriya
cittas.
Furthermore, the 27 mahaggata cittas can be divided into 9 kusala
cittas, 9 vipāka cittas and 9 kiriya cittas according to jāti. These groups
of cittas are also referred to as 9 mahaggata kusala cittas, 9 mahaggata
vipāka cittas and 9 mahaggata kiriya cittas.
The 81 lokiya cittas can be divided into 12 akusala cittas, 17 kusala
cittas, 32 vipāka cittas and 20 kiriya cittas according to jāti. The latter
groups of cittas, being lokiya, are respectively known as 17 lokiya
kusala cittas, 32 lokiya vipāka cittas and 20 lokiya kiriya cittas, respectively.
Now the 89 cittas (brief total) can be divided into 12 akusala cittas,
21 kusala cittas, 36 vipāka cittas and 20 kiriya cittas. The 121 cittas
(broad total) can be divided into 12 akusala cittas, 37 kusala cittas, 52
vipāka cittas and 20 kiriya cittas according to birth (jāti).