Szngzllaritzes 81[ll] T. Damour, A. Kleinschmidt and H. Nicolai, “Hidden symmetries and the fermi-
onic sector of eleven-dimensional supergravity,” Phys. Lett. B 634 (2006) 319-324
[arXiv: hep-th/05 12 1631.
[12] S. de Buyl, M. Henneaux and L. Paulot, “Extended E(8) invariance of 11-dimensional
supergravity,” [arXiv:hep-th/0512292].