Serre J.-P.: Algébre Locale Multiplicités
. Lecture Notes Mathematics 11, 1975. Zbl 0296.13018
 Horák M., Kolář I.: On the higher order Cartan-Poincaré forms. to appear.
 Krupka D.: Lepagean forms of the calculus of variations and the structure of the Euler-Lagrange mapping. to appear.
 Chrastina J.: A double complex related with a system of partial differential equations I
. Zbl 0539.58001
 Chгastina J.: An other approach to the classical calculus of variations. I. Lagrange problem. to appear.