@article{RSMUP_1978__59__97_0,
     author = {Hager, Anthony W. and Robertson, Lewis C.},
     title = {Extremal units in an archimedean {Riesz} space},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {97--115},
     publisher = {Seminario Matematico of the University of Padua},
     volume = {59},
     year = {1978},
     mrnumber = {547081},
     zbl = {0428.46008},
     language = {en},
     url = {http://archive.numdam.org/item/RSMUP_1978__59__97_0/}
}