@article{RSMUP_2017__138__91_0,
     author = {Cimatti, Giovanni},
     title = {Remark on the equations of axially symmetric gravitational fields},
     journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova},
     pages = {91--100},
     publisher = {European Mathematical Society Publishing House},
     address = {Zuerich, Switzerland},
     volume = {138},
     year = {2017},
     doi = {10.4171/RSMUP/138-4},
     mrnumber = {3743246},
     zbl = {1384.83009},
     url = {http://archive.numdam.org/articles/10.4171/RSMUP/138-4/}
}