I published two commentaries on the Yoga Sutras under the titles of:

Yoga Sutras of Patanjali

Meditation Expertise

For indirect references to kundalini by Patanjali, see these verses:

Yoga Sutras 3.30-34

Chapter 3

Verse 30

नाभिचक्रे कायव्यूहज्ञानम्॥३०॥

nābhicakre kāyavyūhajñānam

By complete restraint of the mento-emotional energy  in relation to the focusing on the navel energy-gyrating center,  the yogi gets knowledge about the layout of his body.

Verse 31

कण्ठकूपे क्षुत्पिपासानिवृत्तिः॥३१॥

kaṇṭhakūpe kṣutpipāsā nivṛttiḥ

By the complete restraint of the mento-emotional energy  in focusing on the gullet,  a yogi causes the suppression of hunger and thirst.

Verse 32

कूर्मनाड्यां स्थैर्यम्॥३२॥

kūrmanāḍyāṃ sthairyam

By the complete restraint of the mento-emotional energy  in focusing on the kurma nāḍi subtle nerve,  a yogi acquires steadiness of his psyche.

Verse 33

मूर्धज्योतिषि सिद्धदर्शनम्॥३३॥

mūrdhajyotiṣi siddhadarśanam

By the complete restraint of the mento-emotional energy  as it is focused  on the shining light in the head of the subtle body,  a yogi gets views of the perfected beings.

Verse 34

प्रातिभाद्वा सर्वम्॥३४॥

prātibhād vā sarvam

By complete restraint of the mento-emotional energy,  while focusing on the shining organ of divination  in the head of the subtle body,  the yogin is able to know all reality.