Brihat Parashara Hora Shastra
तदाऽन्यत्र स्थितं नाथं परिगृह्य दशां नयेत् । द्वावप्यन्यर्क्षगौ तौ चेत् तमोर्मध्ये च यो बली ॥ १६०॥
If one Grah be in his own Rāśi and the other in any other Rāśi, the Dasha will be of the number of years counted, from the above first Rāśi to the other. If the Lords are in different Rāśis, the counting is to be done up to the Rāśi, which is stronger.
english translation
tadA'nyatra sthitaM nAthaM parigRhya dazAM nayet । dvAvapyanyarkSagau tau cet tamormadhye ca yo balI ॥ 160॥
hk transliteration by Sanscript