@article{AUPO_1974__14_1_a2,
     author = {Krbi\v{l}a, Jaroslav},
     title = {Quadratic functionals with {Euler's} equation $(py')' + qy = 0$},
     journal = {Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica},
     pages = {31--43},
     publisher = {mathdoc},
     volume = {14},
     number = {1},
     year = {1974},
     mrnumber = {0379983},
     zbl = {0326.34008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUPO_1974__14_1_a2/}
}