2015 book
The inverse problem of the calculus of variations: Local and global theory
open access via link.springer.com (publisher PDF)
Source: NC State University Libraries
Added: August 6, 2018
The Helmholtz Conditions and the Method of Controlled Lagrangians.- The Sonin-Douglas Problem.- Inverse Variational Problem and Symmetry in Action: The Relativistic Third Order Dynamics.- Variational Principles for Immersed Submanifolds.- Source Forms and their Variational Completions.- First-Order Variational Sequences in Field Theory.