@article{10_4153_CJM_1973_110_x,
     author = {Willett, D.},
     title = {A {Generalization} of {\v{C}aplygin's} {Inequality} with {Applications} to {Singular} {Boundary} {Value} {Problems}},
     journal = {Canadian journal of mathematics},
     pages = {1024--1039},
     year = {1973},
     volume = {25},
     number = {5},
     doi = {10.4153/CJM-1973-110-x},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1973-110-x/}
}