@article{10_4064_aa149_2_3,
     author = {Paul M. Voutier},
     title = {Effective irrationality measures and
 approximation by algebraic conjugates},
     journal = {Acta Arithmetica},
     pages = {131--143},
     publisher = {mathdoc},
     volume = {149},
     number = {2},
     year = {2011},
     doi = {10.4064/aa149-2-3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa149-2-3/}
}