Nata, J. H., N. E. Suriani, and M. R. Darmawan. “Differences in Marketing Communication Activities at Sheraton Surabaya Hotel & Towers in the Middle of COVID-19 Pandemic”. TIJAB (The International Journal of Applied Business), vol. 4, no. 2, Nov. 2020, pp. 125-38, doi:10.20473/tijab.V4.I2.2020.125-138.