@article{AMI_2013_41_a20,
     author = {Florian Luca and Pantelimon St\u{a}nic\u{a} and Aynur Yal\c{c}iner},
     title = {When do the {Fibonacci} invertible classes modulo {M} form a subgroup?},
     journal = {Annales mathematicae et informaticae},
     pages = {265--270},
     publisher = {mathdoc},
     volume = {41},
     year = {2013},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AMI_2013_41_a20/}
}