Brihat Parashara Hora Shastra
अर्कांश कर्कलग्ने पञ्चोत्तरी मता । मित्रर्क्षाज्जन्मभं यावत् संख्या सप्तविभाजिता ॥ २९॥
This Dasha is considered suitable for those, whose Lagn is Kark and also in the Kark Dvadashāńś. Count from Anuradha up to the Janm Nakshatr and divide the number by 7.
english translation
arkAMza karkalagne paJcottarI matA । mitrarkSAjjanmabhaM yAvat saMkhyA saptavibhAjitA ॥ 29॥
hk transliteration by Sanscript