@article{M2AN_1981__15_2_177_0,
     author = {Valerio, Vladimiro},
     title = {On the partitioned matrix $\begin{pmatrix}O&A\\A^\ast &Q\end{pmatrix}$ and its associated system $AX=T, A^\ast Y+QX = Z$},
     journal = {RAIRO. Analyse num\'erique},
     pages = {177--184},
     publisher = {Centrale des revues, Dunod-Gauthier-Villars},
     address = {Montreuil},
     volume = {15},
     number = {2},
     year = {1981},
     mrnumber = {618822},
     zbl = {0458.15003},
     language = {en},
     url = {http://www.numdam.org/item/M2AN_1981__15_2_177_0/}
}