@article{10_4064_cm126_1_10,
     author = {Florian Luca and Carl Pomerance},
     title = {Acknowledgment of priority: {{\textquotedblleft}On} some problems of {M\k{a}kowski{\textendash}Schinzel} and {Erd\H{o}s} concerning the arithmetical functions $\phi$ and $\sigma${\textquotedblright}  {(Colloq.} {Math.} 92 (2002), 111{\textendash}130)},
     journal = {Colloquium Mathematicum},
     pages = {139--139},
     publisher = {mathdoc},
     volume = {126},
     number = {1},
     year = {2012},
     doi = {10.4064/cm126-1-10},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm126-1-10/}
}