Bibliography
Drioton, Étienne (1933), Essai sur la cryptographie privée de la fin de la XVIIIe dynastie. Revue d'égyptologie 1, p. 49, no. 181, D. considers the sign a variant of N18.
Roberson, J.A. (2020), Enigmatic writing in the Egyptian New Kingdom II: a lexicon of ancient Egyptian cryptography of the New Kingdom. With contributions by David Klotz. Zeitschrift für ägyptische Sprache und Altertumskunde - Beihefte 12 (2), p. 182, sign Z8.1, R. follows the reading of Drioton.