The Tipiṭaka in Three Languages

Hetudukaajjhattāraṁmaṇattika

Abhidhammapiṭaka · Paṭṭhāna (5) · Vol. 44 · Section 861

[861] A phenomenon (dhamma) that is a root (hetu) and has an external object (bahiddhārammaṇa) is a condition for a phenomenon that is a root and has an external object by root condition (hetu-paccaya). (There are) three.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 5 other places