1. The scientific foundations of youth development;Benson,2001
2. Experimental and quasi-experimental designs for research;Campbell,1963
3. Centers for Disease Control and Prevention(n.d.). CDC Unified Process Project Management Guide. Downloaded on June 24, 2019 from https://www2a.cdc/gov/cdcup/library/pmg/frame_page.htm
4. Managing clinical trials;Farrell;Trials,2010
5. Threats to the internal validity of experimental and quasi-experimental research in healthcare;Flannelly;Journal of Health Care Chaplaincy,2018