Quadratic Differential Systems on $\mathbb{R}^{3}$ Having a Semisimple   Derivation
  The classification, up to a center-affinity, of the homogeneous quadratic differential systems defined on $\mathbb{R}^{3}$ that have at least a semisimple nonsingular derivation, is achieved. It is proved that there exist four affine-equivalence classes of such systems, only. 
Ilie Burdujan
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