@article{BMMS_2004_27_1_a4,
     author = {Supama and Soeparna Darmawijaya},
     title = {Superposition {Operators} on},
     journal = {Bulletin of the Malaysian Mathematical Society},
     year = {2004},
     volume = {27},
     number = {1},
     url = {http://geodesic.mathdoc.fr/item/BMMS_2004_27_1_a4/}
}