The AMS website will be down on Saturday December 11th from 8:30 am to approximately 11:30 am for maintenance.
ISSN 1088-9485(online) ISSN 0273-0979(print)
Sufficient conditions for a non-regular problem in the calculus of variations
G. M. Ewing
Bull. Amer. Math. Soc. 43 (1937), 371-376
Full-text PDF Free Access