Zborowski, Grzegorz. “Construction of an A-Manifold on a Principal Torus Bundle”. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica 12 (December 31, 2013): 5–19. Accessed October 31, 2026. https://studmath.uken.krakow.pl/article/view/13174.