@article{10_4064_aa163_3_1,
     author = {R. Balasubramanian and Florian Luca and Dimbinaina Ralaivaosaona},
     title = {On the sum of the first $n$ values of the {Euler} function},
     journal = {Acta Arithmetica},
     pages = {199--201},
     publisher = {mathdoc},
     volume = {163},
     number = {3},
     year = {2014},
     doi = {10.4064/aa163-3-1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa163-3-1/}
}