Shiva Purana
प्रणवं ध्वनिलिंगं तु नादलिंगं स्वयंभुवः । बिंदुलिंगं तु यंत्रं स्यान्मकारं तु प्रतिष्ठितम् ११३ ।
The Pranava (Om) is the sound-lingam, the Naada-lingam is the self-manifested, and the Bindulinga is the yantra. The Makaralinga is established in the form of the symbol.
english translation
praNavaM dhvaniliMgaM tu nAdaliMgaM svayaMbhuvaH । biMduliMgaM tu yaMtraM syAnmakAraM tu pratiSThitam 113 ।
hk transliteration by Sanscript