Dear Antonia,
Not sure about the precise reference you seek, but this article may be of interest:
THE CREATIVE ROLE OF THE GODDESS VĀC IN THE ṚGVEDA
W. Norman Brown
Mahfil
Vol. 7, No. 3/4, SANSKRIT ISSUE (Fall - Winter 1971), pp. 19-27
Available on JSTOR.
good luck,
Matthew
Matthew Kapstein
Directeur
d'études,
Ecole Pratique des Hautes Etudes
Numata Visiting Professor of Buddhist Studies,
The University of Chicago