References
The statements of  Bhagavad-gītā As It Is  are all confirmed by standard Vedic authorities. The following authentic scriptures are quoted in  Bhagavad-gītā As It Is  on the pages listed.
Atharva-veda
503
Bhakti-ti-rasāmrta-sindhu  (Rūpa Gosvāmī)
231,274,318,340,366,387,592
Brahma-samhitā
12-13, 74, 176, 214, 220, 228, 323, 339, 372, 451, 457, 459, 637
Brhan-Nāradīya Purāṇa
320
Caitanya-caritāmrta  (Krṣṇadāsa Kavirāja Gosvāmī)
24, 82, 125, 226, 227
Garga  Upaniṣad
80,454
Katha Upaniṣad
86-87, 99, 100, 111, 3711
Kürma Purāṇa
489
Mādhyandi-nāyana-śruti
703
Mahābhārata
215
Mokşa-dharma
504
Mundaka Upanisad
95, 102-103
Nārada-pañcarātra
340
Nārāyaṇīya
603
Nirukti  (Vedic dictionary))
1۲8-1۲9
863