Brihat Jataka
दृक्काणहोरानवभागसंज्ञास्त्रिंशांशकद्वादशसंज्ञिताश्च ॥ क्षेत्रं च यद्यस्य स तस्य वर्गो होरेति लग्नं भवनस्य चार्द्धम् ॥ १-९ ॥
Vargas ie the divisions of signs are (9) Dreshkan (Decante ie 1/3rd part of a sign). Hora (Half of a sign), Navamsha (l/9th part of a sign) Trimshamsha (l/30th part of a sign), Dwadashamsha (1/12th part of a sign). A planet located in a particular sign and having the varga also of the same sign is called "Vargottam". The term "Hora" means Ascendant as well as the half of any sign (half of 30 degrees).
english translation
dRkkANahorAnavabhAgasaMjJAstriMzAMzakadvAdazasaMjJitAzca ॥ kSetraM ca yadyasya sa tasya vargo horeti lagnaM bhavanasya cArddham ॥ 1-9 ॥
hk transliteration by Sanscript