Brihat Parashara Hora Shastra
लग्नादिव्ययपर्यन्तं भानां चरदशां ब्रुवे । तस्मात् तदीशपर्यन्तं संख्यामत्र दशां विदुः ॥ १५५॥
Now I shall describe the Chara Daśā of the zodiacal signs from the Ascendant (Lagna) up to the twelfth house. The duration of each Daśā is determined by counting from the sign itself to the sign occupied by its lord.
english translation
lagnAdivyayaparyantaM bhAnAM caradazAM bruve । tasmAt tadIzaparyantaM saMkhyAmatra dazAM viduH ॥ 155॥
hk transliteration by Sanscript