Surya Siddhanta
सूर्याद् अभ्यधिकाः पश्चाद् अस्तम् जीवकुजार्जजाः। ऊनाः प्रागुदयम् यान्ति शुक्रज्ञौ वक्रिणौ तथा॥
If the true longtitude of the planets (grahaspasta) is greater than the longtitude of the sun (suryaspasta), Jupiter, Mars and Saturn sets in the west. If their longtitude is less than that of the sun, they rise in the east. Similar is the case with retrograde Venus and Mercury.
english translation
sUryAd abhyadhikAH pazcAd astam jIvakujArjajAH। UnAH prAgudayam yAnti zukrajJau vakriNau tathA॥
hk transliteration by Sanscript