@article{10_4064_aa103_1_6,
     author = {Derong Qiu and Xianke Zhang},
     title = {$L$-series and their $2$-adic valuations at $s=1$
attached to {CM} elliptic curves},
     journal = {Acta Arithmetica},
     pages = {79--95},
     publisher = {mathdoc},
     volume = {103},
     number = {1},
     year = {2002},
     doi = {10.4064/aa103-1-6},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa103-1-6/}
}