माण्डूक्योपनिषद्
Mandukya Upanishad
Twelve verses on Om and the four states of consciousness — waking, dream, deep sleep, and turiya.
GRETIL e-text (sa_mANDUkyopaniSad-alt), mula extracted from the commentary edition · Sanskrit e-text: GRETIL, CC BY-NC-SA 4.0 (NonCommercial — see provenance)