Surya Siddhanta
शशाङ्ककक्षागुणितो भाजितो वा +अर्ककक्षया । विष्कम्भश् चन्द्रकक्षायाम् तिथ्याप्ता मानलिप्तिका॥
The rectified diameter of the Sun multiplied by his revolutions (in a Kalpa) and divided by the Moon's revolutions (in that cycle), or multiplied by the periphery of the Moon's orbit and divided by that of the Sun, becomes the diameter of the Sun at the Moon's orbit. Tbe diameter of the Sun at the Moon's orbit and the Moon's rectified diameter divided by 15, give the numbers of minutes contained in the diameters (of the discs of the Sun and the Moon respectively).
english translation
zazAGkakakSAguNito bhAjito vA +arkakakSayA । viSkambhaz candrakakSAyAm tithyAptA mAnaliptikA॥
hk transliteration by Sanscript