Brihat Parashara Hora Shastra
अष्टमे मन्दसंयुक्ते तस्माद्वा द्वादशे कुजः । त्रिंशाब्दे दशमेऽब्दे तु स्फोटकादि विनिर्दिशेत् ॥ २४॥
Śani in Randhr, as Mangal is in Yuvati, all cause small-pox in Karm year and in 30th year of age.
english translation
aSTame mandasaMyukte tasmAdvA dvAdaze kujaH । triMzAbde dazame'bde tu sphoTakAdi vinirdizet ॥ 24॥
hk transliteration by Sanscript