1. Bryant, R.L.: Some remarks on $$G_2$$-structures. In: Proceedings of Gökova Geometry-Topology Conference 2005, pp. 75–109. Gökova Geometry/Topology Conference (GGT), Gökova (2006)
2. Cartan, H., Eilenberg, S.: Homological algebra. Princeton Landmarks in Mathematics. Princeton University Press, Princeton, NJ (1999). With an appendix by David A. Buchsbaum, Reprint of the 1956 original
3. Colombo, F., Sabadini, I., Struppa, D.C.: A new functional calculus for noncommuting operators. J. Funct. Anal. 254(8), 2255–2274 (2008)
4. Colombo, F., Sabadini, I., Struppa, D.C.: Noncommutative functional calculus, volume 289 of Progress in Mathematics. Birkhäuser/Springer Basel AG, Basel (2011). Theory and applications of slice hyperholomorphic functions
5. De Leo, S., Abdel-Khalek, K.: Octonionic quantum mechanics and complex geometry. Progr. Theor. Phys. 96(4), 823–831 (1996)