Surya Siddhanta
विक्षेपापक्रमैकत्वे क्रान्तिर् विक्षेपसम्युता ।दिग्भेदे वियुता स्पष्टा भास्करस्य यथागता ॥
The (mean) declination (of a planet or the declination found by computation from its corresponding point in the ecliptic) increased or diminished by its latitude, according as they are both of the same or different denominations, becomes the true (declination of the planet). But the Sun's (true declination) is (the same as) his mean declination.
english translation
vikSepApakramaikatve krAntir vikSepasamyutA ।digbhede viyutA spaSTA bhAskarasya yathAgatA ॥
hk transliteration by Sanscript