... to quote the U.S. Copyright
Office's "fair use" FAQ:
47.How much of someone else's work can I use without getting permission?
Under the fair use doctrine of the U.S. copyright statute, it is
permissible to use limited portions of a work including quotes, for purposes
such as commentary, criticism, news reporting, and scholarly reports. There
are no legal rules permitting the use of a specific number of words, a
certain number of musical notes, or percentages of a work. Whether a
particular use qualifies as fair use depends on all the circumstances. See
Circular 21 and FL 102.<<