Astanga Hrudaya
स्तनौ रक्तपथश्चेति नारीणामधिकंत्रयम्। जीवितायतनान्यन्तः स्रोतांस्याहुस्त्रयोदश॥४१॥
there are three more, two in the breasts and one for the passage of menstrual blood. Abhyantra Srotas - internal channels: Srotas which are internal are said to be thirteen and are seats of the life they are,
english translation
stanau raktapathazceti nArINAmadhikaMtrayam। jIvitAyatanAnyantaH srotAMsyAhustrayodaza॥41॥
hk transliteration by Sanscript