From Columbia University:
If you are seeking to use a copyrighted work, you may have to obtain permission from the copyright owner. The owner may be the original creator of the work or that person’s employer. The original author may also have transferred the copyright to a publisher or some other party. In some instances, you may contact the owner directly. In other cases, you can secure permission on behalf of the owner by contacting an industry licensing agency or a publisher. Sometimes, the copyright owner may require a fee or impose other conditions. You have to decide if the cost and conditions are acceptable, and you should feel free to negotiate.
The pages in this section offer information on:
In most cases, the quest for permission will go smoothly, and may demand only time and bother. However, some situations become complicated, especially if you cannot locate the owner or get a response. See Complex Searches for further discussion of the potential complications of seeking permissions.
Keep in mind that you might not need permission if: