Brihat Parashara Hora Shastra
जन्मर्क्ष च त्रिभिर्युक्तं वसुभिर्भागमाहरेत् । एकादिशेषे विज्ञेया योगिन्योः मङ्गलादिकाः ॥ १९९॥
Add 3 to the Janm Nakshatr and divide it by 8. The remainder will indicate the Yogini Dasha of Mangal, etc.
english translation
janmarkSa ca tribhiryuktaM vasubhirbhAgamAharet । ekAdizeSe vijJeyA yoginyoH maGgalAdikAH ॥ 199॥
hk transliteration by Sanscript