Surya Siddhanta
तथा चासुरभागे तु मिथुने कर्कटे स्थितः। नष्टच्छाया महीवृत्तपादे दर्शनम् आदिशेत्॥
- So also, in the hemisphere of the demons, when in Gemini and Cancer : in the quarter of the earth's circumference where her shadow is lost, the sun may be shown to be visible.
english translation