Natyashastra
स्वरसाधारणश्चापि काकल्यन्तरसंज्ञया । निषादगान्धारकृतौ षड्जमध्यमयोरपि ॥ ८ ॥
The note called Svarasādhāraṇa, also known as Kākalī, is produced by the combination of Niṣāda and Gāndhāra with Ṣaḍja and Madhyama.
english translation
svarasAdhAraNazcApi kAkalyantarasaMjJayA । niSAdagAndhArakRtau SaDjamadhyamayorapi ॥ 8 ॥
hk transliteration by Sanscript