Brihat Parashara Hora Shastra
सप्तांशपास्त्वोजगृहे गणनीया निजेशतः। युग्मराशौ तु विज्ञेयाः सप्तमर्क्षादिनायकात्॥ १०॥
Saptāńś. The Saptāńś (one seventh of a Rāśi) counting commences from the same Rāśi in the case of an odd Rāśi. It is from the seventh Rāśi thereof, while an even Rāśi is considered.
english translation
saptAMzapAstvojagRhe gaNanIyA nijezataH। yugmarAzau tu vijJeyAH saptamarkSAdinAyakAt॥ 10॥
hk transliteration by Sanscript