Note on the two congruences $a{x}^{2}+b{y}^{2}+e\equiv 0$, $a{x}^{2}+b{y}^{2}+c{z}^{2}+d{w}^{2}\equiv 0\phantom{\rule{0.222222em}{0ex}}\left(\text{mod.}\phantom{\rule{4pt}{0ex}}p\right)$, where $p$ is an odd prime and $a¬\equiv 0$, $b¬\equiv 0$, $c¬\equiv 0$, $d¬\equiv 0\phantom{\rule{0.222222em}{0ex}}\left(\text{mod.}\phantom{\rule{4pt}{0ex}}p\right)$
Rendiconti del Seminario Matematico della Università di Padova, Tome 18 (1949) , p. 311-315
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