@article{CM_1980__40_2_177_0,
     author = {Pizer, Arnold},
     title = {Theta series and modular forms of level $p^2M$},
     journal = {Compositio Mathematica},
     pages = {177--241},
     publisher = {Sijthoff et Noordhoff International Publishers},
     volume = {40},
     number = {2},
     year = {1980},
     mrnumber = {563541},
     zbl = {0411.10007},
     language = {en},
     url = {http://archive.numdam.org/item/CM_1980__40_2_177_0/}
}