@article{10_4153_CJM_1976_033_3,
     author = {Everitt, W. N.},
     title = {A {Note} on the {Dirichlet} {Condition} for {Second-Order} {Differential} {Expressions}},
     journal = {Canadian journal of mathematics},
     pages = {312--320},
     year = {1976},
     volume = {28},
     number = {2},
     doi = {10.4153/CJM-1976-033-3},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1976-033-3/}
}