Liouville J. [1864] Sur la forme $x^2+y^2+z^2+5t^2$, $x^2+y^2+2z^2+2zt+3t^2$, $x^2+5(y^2+z^2+t^2)$, $2x^2+2xy+3y^2+5z^2+5t^2$, $x^2+y^2+z^2+t^2+u^2+3v^2$, $x^2+3(y^2+z^2+t^2+u^2+v^2)$, $x^2+y^2+z^2+t^2+2u^2+2uv+2v^2$, $2x^2+2xy+2y^2+3(z^2+t^2+u^2+v^2)$, $x^2+y^2+2z^2+2tz+2t^2+3u^2+3v^2$, $x^2+2y^2+2yz+2z^2+3t^2$, $x^2+y^2+z^2+t^2+u^2+2v^2$, $x^2+2(y^2+z^2+t^2+u^2+v^2)$, $x^2+xy+y^2+6z^2+6zt+t^2$. J.M. 9, 1-24, 89-128, 160-182.
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Liouville J. [1864] Sur la forme $2x^2+2xy+2y^2+3z^2+3yt+3t^2$, $x^2+xy+y^2+3z^2+3t^2$, $x^2+y^2+z^2+t^2+2(u^2+v^2)$, $x^2+y^2+2(z^2+t^2+u^2+v^2)$, $x^2+2y^2+3z^2+6t^2$, $x^2+2(y^2+z^2+t^2+u^2)+4v^2$. J.M. 9, 183-184, 223-224, 257-272, 273-280, 299-312.

Liouville J. [1864] Extrait d'une lettre adressée à M. Besge. J.M. 9, 296-298.
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Liouville J. [1865] Sur la forme $x^2+y^2+5z^2+5t^2$, $2x^2+2xy+3y^2+2z^2+2zt+3t^2$, $x^2+y^2+9z^2+9t^2$, $2x^2+2xy+5y^2+2z^2+2zt+5t^2$, $x^2+y^2+a(z^2+t^2)$, $x^2+2y^2+az^2+2at^2$, $x^2+4(y^2+z^2+t^2+u^2+v^2)$, $x^2+y^2+4(z^2+t^2+u^2+v^2)$, $x^2+2y^2+2z^2+4(t^2+u^2+v^2)$, $x^2+y^2+z^2+4(t^2+u^2+v^2)$, $x^2+y^2+2z^2+2t^2+4u^2+4v^2$, $x^2+y^2+2z^2+t^2+4(u^2+v^2)$, $x^2+y^2+z^2+2t^2+2u^2+4v^2$, $x^2+y^2+z^2+t^2+u^2+4v^2$, $x^2+4y^2+4z^2+4t^2+4u^2+16v^2$, $x^2+y^2+6z^2+6t^2$, $2x^2+2y^2+3z^2+3t^2$, $x^2+y^2+z^2+7t^2$. J.M. 10, 1-24, 43-54, 65-80, 145-168, 203-208, 234, 359-360.