When in doubt, obtain prior permission of the copyright holder. Generally, the author or publisher of a work owns the copyright. It is important to properly credit the source of a work. Remember, giving credit to an author is not a substitute for either getting authorization from the copyright owner or paying royalties to be allowed to use the material.
First, identify, locate and confirm the copyright owner allowing plenty of time before your anticipated use. Then, request and receive permission in writing, keeping a record of all correspondence.
Photo: “Question Mark Graffiti” by Bilal Kamoon CC BY 2.0