P. Sudibjo, S. Sumaryanto, G. Guntur, E. R. Sukamti, E. S. Kriswanto, and S. Nopembri, “Sports while sunbathing to increase immunity during the Covid-19 pandemic”, INT J HUM RESPONSIBILITIES EDUC SPORT SCI, vol. 2, no. 1, pp. 1–8, Oct. 2021.