The NAXOS album of MARTINU: Flute Trios / Promenades / Madrigal
Sonata, as performed by the Feinstein Ensemble, can be found on the
page
http://www.naxos.com/catalogue/item.asp?item_code=8.553459#
The tracks are available there as paid downloads, and there are also
links to a variety of purchasing options.
Best wishes,
Joel Feinstein