When you ask for a rights-holder's permission to re-use their work, be prepared to negotiate a fee, and/or accept their terms and conditions.
Reaching an agreement may depend on your intended use:
Scholarly publishers and academic rights-holders often respond positively to requests to reproduce their material in a context which raises the creator's profile, such as teaching materials or a critical review.
Contacting the rights-holder
Many publishers offer a dedicated service to process requests for permission to reproduce their material. Look for a form or email address on their website.
Watch (Writers, Artists and Their Copyright Holders) is "a database of copyright contacts for writers, artists and prominent figures in other creative fields", maintained by the University of Reading and the University of Texas at Austin.
The partner service Fob (Firms Out of Business) provides information about publishing concerns and literacy agencies no longer operational.