The interview featured in this piece was part of a larger interview conducted by Leonard Feather with Oscar Peterson and Lester Young.  It was published November 2nd, 1951 in Downbeat Magazine.  The full interview can be found at the Leonard Feather Jazz Collection, Part of the International Jazz Collections at the University of Idaho Library, or

http://digital.lib.uidaho.edu/cdm/ref/collection/lfc/id/6901.