Goh, F. W., A. C. Jungck, and J. R. Stevens. “Pro Tip: Screen-Based Payment Methods Increase Negative Feelings in Consumers But Do Not Increase Tip Sizes”. European Journal of Behavioral Sciences, vol. 4, no. 4, Dec. 2021, pp. 1-21, doi:10.33422/ejbs.v4i4.678.