With respect to sources for Star Trek episodes: how did the
contributing editors have access to those episodes?
I've said before and still feel that if the episodes are available on
commercially purchasable videos, they have been "published" in a way
that is comparable to a print book.
So I believe that movie and TV episodes should be referenced to
published DVDs, _with proper identification_ (ASIN number or
publisher and catalog number) and _the time, to the minute_ at which
the line of dialog or event occurs.
Citations (with page numbers for print sources, or timings for video)
serve two related purposes. First, if you do not actually plan to
verify the citation, the fact that a timing is supplied is evidence
(assuming good faith) that the contributing editor consulted the
source rather than relying on memory. Second, if you do wish to
verify the citation, it means that once you have obtained a copy of
the source you can verify the citation with a reasonable amount of work.
A typical print book that is in print can be purchased for a modest
but not negligible sum and can be acquired in days to weeks. In or
out of print, depending on its obscurity, it may be available in a
few hours at a local public library, available in days through
interlibrary loan, or available only in big research libraries.
In most cases the amount of money and time required to access a DVD
is comparable.
If the episode has _not_ been published on commercial videos, then
IMHO it is not verifiable. Of course, published print sources that
describe the episode are fine.