Narapatijayacarya 4.4.25

4.4.25

ghaṅchā raudrage vedhe ṣaṇaṭhā hastage grahe ||
dhaphaḍāḥ pūrvāṣāechāyāṃ thajhañā bhādra uttare ||
avarṇādisvaradvandveṣvekavedhe dvayorvyadhaḥ ||
yuktasvarātmake vedhe tvanusvāravisargayoḥ ||

Gha-ṅa-cha [are pierced] when the piercing planet is in Ārdrā; ṣa-ṇa-ṭha when the planet is in Hasta; / dha-pha-ḍha in Pūrvāṣāḍhā; tha-jha-ña in Uttarabhadrapadā. / In the pairs of vowels beginning with the phoneme a, when one is pierced, there is piercing of both; / and in the astrological piercing of an entity made of combined vowels, [the same applies] to the anusvāra and visarga.