I was just thumbing through Corrigan's Writing About Film and see lots of
images which I assume are "grabs."  He cites the film, but there is no
indication of permission being granted to use them.  I think he's on thin
ice.  He does cite permissions for the stills he has used from MOMA and
other venues.

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Online resources for film/TV studies may be found at ScreenSite
http://www.tcf.ua.edu/ScreenSite