Brihat Parashara Hora Shastra
षष्टिरिष्वब्धयस्त्रिंशदाकृतिस्तिथयो गजाः । चत्वारो द्वौ च शून्यं च शुभमेतत्फलं गृहे ॥ ८॥
If Subhanka is deducted from 60, Asubhanka (Asubh Pankthi, inauspicious points) will emerge.
english translation
SaSTiriSvabdhayastriMzadAkRtistithayo gajAH । catvAro dvau ca zUnyaM ca zubhametatphalaM gRhe ॥ 8॥
hk transliteration by Sanscript