Watthanakorn, Y., and S. . Pasiphol. “Development of Test Item Specifications of the 21st Century Collaboration Skills for Undergraduate Students”. An Online Journal of Education, vol. 16, no. 2, Nov. 2021, p. OJED1602036 (11 pages), https://so01.tci-thaijo.org/index.php/OJED/article/view/251865.