Siva Samhita

"In the pericarp of the (Mul)adhara lotus there is a triangular beautiful yoni, hidden and kept secret. In it is the supreme goddess Kundalini of the form of electricity, in a coil. It has three coils and a half (like a serpent) and is in the mouth of Sushumna. It represents the creative force of the world, and is always engaged in creation."
Siva Samhita
Chapter 2 Verse 22-24
All the great self-realized souls and scriptures have spoken about kundalini and/or self-realization. For example:
