@article{AM2_1981__22_136867,
     author = {Ray Redheffer},
     title = {Increasing functions.},
     journal = {Aequationes mathematicae},
     pages = {119--133},
     publisher = {mathdoc},
     volume = {22},
     year = {1981},
     zbl = {0489.26007},
     url = {http://geodesic.mathdoc.fr/item/AM2_1981__22_136867/}
}