Brihat Samhita
शतं एकाधिकं एके सहस्रं अपरे वदन्ति केतूनाम् । बहुरूपं एकं एव प्राह मुनिर्नारदः केतुम् ॥ ११-०५ ॥
Some writers say that the Ketus are 101 in number; others say that they are 1,000 in number; Nārada says that there is but one Ketu which appears in various shapes at various times.
english translation
zataM ekAdhikaM eke sahasraM apare vadanti ketUnAm । bahurUpaM ekaM eva prAha munirnAradaH ketum ॥ 11-05 ॥
hk transliteration by Sanscript