BogolyubovN. N., & PrykarpatskyA. K. (2007). Generalized de Rham-Hodge complexes, the related characteristic Chern classes, and some applications to integrable multidimensional differential systems on Riemannian manifolds. Ukrains’kyi Matematychnyi Zhurnal, 59(3), 327–344. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/3310