There is an excellent, thorough, and relatively recent discussion of the issue in a student note by Peter Metis.' These remarks supplement and update that discussion.
Hauser, Gregory F.
"Section 1782 Of Title 28 (U.S. Code): Is There A Discoverability Requirement?,"
ILSA Journal of International & Comparative Law: Vol. 4
, Article 20.
Available at: https://nsuworks.nova.edu/ilsajournal/vol4/iss2/20