Suhartini, Dwi, et al. “Utilization of Digital Marketing for Micro, Small, and Medium Enterprises (UMKM) Affected by the Covid-19 Pandemic in Gubeng District, Surabaya City”. Nusantara Science and Technology Proceedings, vol. 2022, no. 24, May 2022, pp. 50-56, https://doi.org/10.11594/nstp.2022.2409.