Nievergelt 2002, p. 158 Nievergelt, Yves (2002), Foundations of Logic and Mathematics: Applications to Computer Science and Cryptography, Springer-Verlag
Flaška et al. 2007, p.1 Lemma 1.1 (iv). This source refers to asymmetric relations as "strictly antisymmetric". Flaška, V.; Ježek, J.; Kepka, T.; Kortelainen, J. (2007). Transitive Closures of Binary Relations I(PDF). Prague: School of Mathematics – Physics Charles University. Archived from the original(PDF) on 2013-11-02.
Flaška et al. 2007, p.1 Lemma 1.1 (iv). This source refers to asymmetric relations as "strictly antisymmetric". Flaška, V.; Ježek, J.; Kepka, T.; Kortelainen, J. (2007). Transitive Closures of Binary Relations I(PDF). Prague: School of Mathematics – Physics Charles University. Archived from the original(PDF) on 2013-11-02.