Chyung, Seung Youn Yonnie; Roberts, Katherine; Swanson, Ieva; Hankinson, Andrea (2017). "Evidence-Based Survey Design: The Use of a Midpoint on the Likert Scale". Performance Improvement. 56 (10): 15-23. doi:10.1002/pfi.21727. ISSN1090-8811.
Chyung, Seung Youn Yonnie; Roberts, Katherine; Swanson, Ieva; Hankinson, Andrea (2017). "Evidence-Based Survey Design: The Use of a Midpoint on the Likert Scale". Performance Improvement. 56 (10): 15-23. doi:10.1002/pfi.21727. ISSN1090-8811.