CC Ādi 5.24

vāsudeva-saṅkarṣaṇa-pradyumnāniruddha
sarva-catur-vyūha-aṁśī, turīya, viśuddha
Word for word: 
vāsudeva — Lord Vāsudeva; saṅkarṣaṇa — Lord Saṅkarṣaṇa; pradyumna — Lord Pradyumna; aniruddha — and Lord Aniruddha; sarva-catuḥ-vyūha — of all other quadruple expansions; aṁśī — source; turīya — transcendental; viśuddha — pure.
Translation: 
Vāsudeva, Saṅkarṣaṇa, Pradyumna and Aniruddha are the primary quadruple forms, from whom all other quadruple forms are manifested. They are all purely transcendental.