@article{RSMUP_1977__57__75_0,
     author = {Ursini, Aldo},
     title = {A sequence of theories for arithmetic whose union is complete},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {75--92},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {57},
     year = {1977},
     mrnumber = {526185},
     zbl = {0411.03053},
     language = {en},
     url = {http://www.numdam.org/item/RSMUP_1977__57__75_0/}
}