D. Wahyuningtyas, W. Sumarno, R. Asih, F. Endriana, K. Windiarti, and N. Mafruudloh, “An Analysis of the English Speaking and Writing Skill Level of Tour Guides in Trenggalek’s Tourist Villages”, Journey, vol. 5, no. 2, pp. 293–303, Oct. 2022.