[5] Borowiec, A., Ferraris, M., Francaviglia, M., Palese, M.: 
Conservation laws for non-global Lagrangians. Univ. Iagel. Acta Math., 41, 2003, 319-331 
MR 2084774 | 
Zbl 1060.70034[11] Eck, D.J.: 
Gauge-natural bundles and generalized gauge theories. Mem. Amer. Math. Soc., 247, 1981, 1-48 
MR 0632164 | 
Zbl 0493.53052[13] Ferraris, M., Francaviglia, M., Palese, M., Winterroth, E.: 
Canonical connections in gauge-natural field theories. Int. J. Geom. Methods Mod. Phys., 5, 6, 2008, 973-988 
DOI 10.1142/S0219887808003144 | 
MR 2453935 | 
Zbl 1175.58006[14] Ferraris, M., Francaviglia, M., Palese, M., Winterroth, E.: 
Gauge-natural Noether currents and connection fields. Int. J. Geom. Methods Mod. Phys., 8, 1, 2011, 177-185 
DOI 10.1142/S0219887811005075 | 
MR 2782884 | 
Zbl 1215.58005[15] Ferraris, M., Francaviglia, M., Raiteri, M.: 
Conserved Quantities from the Equations of Motion (with applications to natural and gauge natural theories of gravitation). Classical Quant. Grav., 20, 2003, 4043-4066 
DOI 10.1088/0264-9381/20/18/312 | 
MR 2017333[16] Ferraris, M., Palese, M., Winterroth, E.: 
Local variational problems and conservation laws. Diff. Geom. Appl, 29, 2011, S80-S85 
MR 2832003 | 
Zbl 1233.58002[17] Francaviglia, M., Palese, M., Winterroth, E.: 
Second variational derivative of gauge-natural invariant Lagrangians and conservation laws. 2005, Differential geometry and its applications, Matfyzpress, Prague, 591-604 
MR 2268969 | 
Zbl 1109.58005[18] Francaviglia, M., Palese, M., Winterroth, E.: 
Variationally equivalent problems and variations of Noether currents. Int. J. Geom. Methods Mod. Phys., 10, 1, 2013, 1220024 (10 pages). 
MR 2998326 | 
Zbl 1271.58008[20] Krupka, D.: 
Variational Sequences on Finite Order Jet Spaces. Proc. Diff. Geom. Appl., 1990, 236-254, J. Janyška, D. Krupka eds., World Sci., Singapore 
MR 1062026 | 
Zbl 0813.58014[21] Krupka, D., Sedenkova, J.: 
Variational sequences and Lepage forms. Differential geometry and its applications, Matfyzpress, Prague, 2005, 617-627 
MR 2271823 | 
Zbl 1115.35349[22] Krupkova, O.: 
Lepage forms in the calculus of variations. Variations, geometry and physics, Nova Sci. Publ., New York, 2009, 27-55 
MR 2523431 | 
Zbl 1208.58019[23] Lepage, Th.H.J.: Sur les champ geodesiques du Calcul de Variations, I, II. Bull. Acad. Roy. Belg., Cl. Sci., 22, 1936, 716-729, 1036--1046
[24] Musilová, J., Lenc, M.: 
Lepage forms in variational theories from Lepage's idea to the variational sequence. Variations, geometry and physics, Nova Sci. Publ., New York, 2009, 3-26 
MR 2523430 | 
Zbl 1208.58001[25] Noether, E.: Invariante Variationsprobleme. Nachr. Ges. Wiss. Gött., Math. Phys. Kl., II, 1918, 235-257
[26] Palese, M., Winterroth, E.: 
Global Generalized Bianchi Identities for Invariant Variational Problems on Gauge-natural Bundles. Arch. Math. (Brno), 41, 3, 2005, 289-310 
MR 2188385 | 
Zbl 1112.58005[28] Palese, M., Winterroth, E.: 
On the relation between the Jacobi morphism and the Hessian in gauge-natural field theories. Teoret. Mat. Fiz., 152, 2, 2007, 377-389, transl. Theoret. and Math. Phys. 152 (2007) 1191--1200 
MR 2429287[29] Palese, M., Winterroth, E.: 
Variational Lie derivative and cohomology classes. AIP Conf. Proc., 1360, 2011, 106-112 
Zbl 1276.70012[30] Palese, M., Winterroth, E., Garrone, E.: 
Second variational derivative of local variational problems and conservation laws. Arch. Math. (Brno), 47, 5, 2011, 395-403 
MR 2876943 | 
Zbl 1265.58008[31] Sardanashvily, G.: Noether conservation laws issue from the gauge invariance of an Euler-Lagrange operator, but not a Lagrangian. arXiv:math-ph/0302012
[32] Witten, E.: 
$2+1$-dimensional gravity as an exactly soluble system. Nucl. Phys., B 311, 1, 1988, 46-78, E. Witten: Quantum field theory and the Jones polynomial. Commun. Math. Phys. 121 (1989) 351-399 
DOI 10.1016/0550-3213(88)90143-5 | 
MR 0974271