Variational Principles in Classical Mechanics,Variational principle | E-19 | Classical mechanics - YouTube,Calculus of Variations: with Applications to Physics and Engineering: Robert Weinstock: 9780486630694: Amazon.com: Books,Principles of Physics Extended, International Student Version: David Halliday; Robert Resnick; Jearl Walker: 9780470561584: Amazon.com: Books,Principles of Physics Extended, International Student Version: David Halliday; Robert Resnick; Jearl Walker: 9780470561584: Amazon.com: Books