Vaisesika Sūtras
Vaisesika Sūtra 7.2.09
anyatarakarmajaḥ ubhayakarmajaḥ saṃyogajaś ca saṃyogaḥ ॥9॥
Combination (saṃyogaḥ) is born of either of the two actions or born of both actions or is born of combination as well.