Srimad Bhagavatam Canto 10, Chapter 18, Text 20

SB 10.18.20

tatra cakruh parivrdhau
 gopa rama-janardanau
krsna-sanghattinah kecid
 asan ramasya capare
 
Translation: 
 
The cowherd boys chose Krsna and Balarama as the leaders of the two parties. Some of the boys were on Krsna’s side, and others joined Balarama.
Srimad Bhagavatam Canto 10, Chapter 18, Text 19
Srimad Bhagavatam Canto 10, Chapter 18, Text 21