Narapatijayacarya 4.4.60

4.4.60

keturaṣṭādaśe prokta ulkā syādekaviṃśatau ||
dvāviṃśatitame kampastrayoviṃśe ca vajrakam ||

Ketu is declared at the eighteenth, and Ulkā will be at the twenty-first; / Kampa is at the twenty-second, and Vajraka at the twenty-third.