@article{MV_1976_28_2_a15,
     author = {J. Achari},
     title = {Extensions of  {\'Ciri\'c's} quasi-constraction in {Banach} spaces},
     journal = {Matemati\v{c}ki vesnik},
     pages = {258 },
     year = {1976},
     volume = {28},
     number = {2},
     url = {http://geodesic.mathdoc.fr/item/MV_1976_28_2_a15/}
}