Plakhta, L. P. “Invariants of Knots, Surfaces in <b>R</b> <sub>3</Sub&gt;, and Foliations”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 59, no. 9, Sept. 2007, pp. 1239–1252, https://umj.imath.kiev.ua/index.php/umj/article/view/3384.