M. Simarmata, F. Tampubolon, Y. J. L. Simamora, H. B. Pakpahan, and D. N. . . Pangaribuan, “Politeness in the Toba Batak Ethnic Panaekkon Saring-Saring Ceremony: Normative Study”, pembahas, vol. 4, no. 5, pp. 1363–1370, Oct. 2025.