Obtaining a copy of a test can take time and may be problematic. Tests and other measurement tools are generally considered either 'published' or 'unpublished'.
Published. Generally commercially available, thus you may need to purchase a copy or obtain permission from the publisher. Many tests require professional credentials or oversight to administer.
Unpublished. Unless specified otherwise, obtain permission from author to use. Copies of tools can sometimes be found in books, journal articles or other collections and can be reproduced.

Permission to use: all testing tools are considered copyrighted, thus you must obtain permission from the copyright holder before using the tool.

Obtaining permission to use an assessment tool is essential and may take time to accomplish.

'Published' tools are generally available from the publisher and may require professional credentials or supervision to administer. Contact information for publishers can be located in TiP, MMY, TestLink or HaPI.  ETS sells copies of tests, see below.

Permission to use 'unpublished' tools is generally sought from the author/creator of the tool. Current contact information for authors is sometimes more difficult to ascertain. Begin with the information in the sources listed in the 'Finding' sources like MMY, try additional online directories, Google, etc.