Cite the thesis-

The rest is made-up authority, unless you're concerned about industry copyright / property law.

Hope this helps,

Matt

You must try to reach the author.

Speak to your committee, you have to find the author or someone whom rights have been granted.

You can write or email the author of the thesis by searching for him/her online or write the university that housed the thesis as an institutional repository that you need to adopt or adapt the instrument in your own study. Also, guarantee them of the wise usage of it as well as given credit to them. I think with this, you should have access to it.

1. Contact with author directly.

2. Consult with any one who used the required questionnaire.

3. In some cases the questionnaire is widely used. Therefore, you may use it with proper citation (From my point of view). But you cannot alter it.

4. Some publishers get the publishing/re use rights from writers. In said case you may directly communicate with publishers.

5. Some questionnaires are openly available for non-commercial and educational use. For example:-

https://www.ijcmph.com/index.php/ijcmph/article/view/675/1042

Now the choice is yours.

Two things.

1. It varies whether you are allowed to just use a questionnaire. Typically if someone publishes it they want it to be used.

2. That is a long time ago. Do you think the scale is still the state-of-the-art?