@article{10_4153_CJM_1972_029_9,
     author = {Lorch, Lee and Muldoon, Martin E. and Szego, Peter},
     title = {Higher {Monotonicity} {Properties} of {Certain} {Sturm-Liouville} {Functions.} {IV}},
     journal = {Canadian journal of mathematics},
     pages = {349--368},
     year = {1972},
     volume = {24},
     number = {2},
     doi = {10.4153/CJM-1972-029-9},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1972-029-9/}
}