Brihat Parashara Hora Shastra
बुधौ राशिकलाधिक्यत् ग्राह्वो नैवात्मकारकः । अंशाधिकः कारकः स्यादल्पभागोऽन्त्यकारकः ॥ ४॥
If the degrees are identical, then the one with more minutes of arc and, if the minutes are also identical, then the one with higher seconds of arc, have to be considered.
english translation
budhau rAzikalAdhikyat grAhvo naivAtmakArakaH । aMzAdhikaH kArakaH syAdalpabhAgo'ntyakArakaH ॥ 4॥
hk transliteration by Sanscript