please how should i write the reference?
Thanks for contacting Ask An Advisor! We're happy to hear our materials have been helpful to you. For information on how to cite CTB, you can take a look at our use policy. I've also copied and pasted an example citation below, though it would need to be updated to reflect the specific sections of the ToolBox you used.
Center for Community Health and Development. (2017). Chapter 3, Section 10: Conducting Concerns Surveys. Lawrence, KS: University of Kansas. Retrieved January 2, 2017, from the Community Tool Box: http://ctb.ku.edu/en/table-of-contents/assessment/assessing-community-needs-and-resources/conduct-concerns-surveys/main.
We wish you the best in writing your thesis!