Desayu Eka Surya, et al. “Teacher Communication Behaviour to Mentally Retarded Students of Sukapura in Bandung City During the Covid-19 Pandemic”. Proceeding of International Conference on Business, Economics, Social Sciences, and Humanities, vol. 4, Dec. 2021, pp. 58-63, https://doi.org/10.34010/icobest.v2i.256.