Srimad Bhagavatam Canto 12, Chapter 11, Text 21

SB 12.11.21

vasudevah sankarsanah
 pradyumnah purusah svayam
aniruddha iti brahman
 murti-vyuho ’bhidhiyate
 
Translation: 
 
Vasudeva, Sankarsana, Pradyumna and Aniruddha are the names of the direct personal expansions of the Supreme Godhead, O brahmana Saunaka.
Srimad Bhagavatam Canto 12, Chapter 11, Text 20
Srimad Bhagavatam Canto 12, Chapter 11, Text 22