Names

like: Nimbarka Sampradaya, Hamsa Sampradaya, Kumara Sampradaya, Catuh Sana Sampradaya and Sanakadi Sampradaya. This faction is one of the four authorised Vaishnava Sampradayas according to the Padma Purana, one of the eighteen principal Puranas.

Four Kumaras as Representative of Root Cube

http://logos_endless_summer.tripod.com/id186.html

General Lessons from the Kumars

http://www.dharmakshetra.com/sages/Kumaras.htm

Prithu Maharaja's Meeting with Four Kumaras

http://vedabase.net/sb/4/22/en1

Nimbarkacarya Songs / Videos

http://kksongs.org/authors/list/nimbarka.html
http://www.ratedesi.com/video/tag/nimbarkacharya

Nimbarka

http://en.wikipedia.org/wiki/Nimbarka

Four Kumaras / Expressions researched

http://en.wikipedia.org/wiki/Four_Kumaras
http://vaniquotes.org/wiki/Four_Kumaras:_Sanaka,_Sanatana,_Sanat-kumara_and_Sanandana