Brihat Parashara Hora Shastra
अथाऽहं सम्प्रवक्ष्यामि स्थिरसंज्ञां दशां द्विज । चरे सप्त स्थिरे चाऽष्टौ द्वन्द्वे नव समाः स्मृताः ॥ १६८॥
Maharishi Parashar said. Now I am going to describe the Sthir Dasha. In this Dasha system 7, 8 and 9 years are the Dasha spans of the Movable (Char), Fixed (Sthir) and Dual (Dvisva Bhava) Rāśis.
english translation
athA'haM sampravakSyAmi sthirasaMjJAM dazAM dvija । care sapta sthire cA'STau dvandve nava samAH smRtAH ॥ 168॥
hk transliteration by Sanscript