Reference to the sloka

[dhilip k]

Namaste 

Would any of you know the source of this sloka - 

दोभ्याँ दोभ्याँ व्रजन्तं व्रजयुवतीजनाह्वानतः प्रोल्लसन्तं, मन्दं मन्दं हसन्तं मृदुमधुरवचो मेति मेति ब्रुवन्तम्। गोपाली पाणिताली तरलितवलयध्वान्मुग्धान्तरालं, वन्दे तं देविमन्दीवरदलिततनुं सुन्दरं नन्दबालम्॥

This sloka is written in Swami Akhandananda ji's book on Sri Krishna Leela Rahasya

He has not given the reference but would like any scholars to let me know the source of this sloka.

Dhilip K