Brihat Parashara Hora Shastra
पञ्चाब्धयः सुराः सूर्याः खण्डकांशाः क्रमादमी । सायनग्रहदोराशितुल्यखण्डयुतिश्च स ॥ १५॥
Ayan Bal. 45, 33 and 12 are the Khandas for calculating Ayan Bal. Add Ayanāńś to the Grah and find out the Bhuja (distance from the nearest equinox). Add the figure, corresponding to the Rāśi (of the Bhuja) to the Bhuja.
english translation
paJcAbdhayaH surAH sUryAH khaNDakAMzAH kramAdamI । sAyanagrahadorAzitulyakhaNDayutizca sa ॥ 15॥
hk transliteration by Sanscript