@article{10_4064_am_19_3_4_611_617,
     author = {J. Topp and W. Ulatowski},
     title = {On functions which sum to zero on semicycles},
     journal = {Applicationes Mathematicae},
     pages = {611--617},
     publisher = {mathdoc},
     volume = {19},
     number = {3-4},
     year = {1987},
     doi = {10.4064/am-19-3-4-611-617},
     zbl = {0719.05044},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/am-19-3-4-611-617/}
}