Drona and Dhara

Bhagavatham
http://vedabase.net/sb/10/8/46/en2

Purana
http://nitaaiveda.com/Compiled_and_Imp_Scriptures/Glories_of_Lord_Krishna/Shri_Nandotsava_Celebrations/Brahma_Vaivarta_Purana.htm 

Samhita
http://www.harekrsna.com/sun/editorials/garga/garga16.htm 

More Detail
http://sixgoswamis.blogspot.com/2015/05/gopala-champu.html 

Reincarnation - Nanda Yasoda

http://fatherguardian.blogspot.com/  

http://motherguardian.blogspot.com/