Shiva Purana
यः कार्त्तिकस्य मार्गस्य पौषस्य तपसस्तथा ॥ तपस्यस्य सिते पक्षे तृतीयायां व्रतं चरेत्॥ ८०॥
He is the path of Kartika and the austerities of Pausa One should observe a vow on the third day of the white fortnight of austerities.
english translation
yaH kArttikasya mArgasya pauSasya tapasastathA ॥ tapasyasya site pakSe tRtIyAyAM vrataM caret॥ 80॥
hk transliteration by Sanscript