Motivated by the construction of new examples of Artin-Schelter regular algebras of global dimension four, Zhang and Zhang [6] introduced an algebra extension AP[y_1, y_2; σ, δ, τ] of A, which they called a double Ore extension. This construction seems to be similar to that of a two-step iterated Ore extension over A. The aim of this article is to describe those double Ore extensions which can be presented as iterated Ore extensions of the form A[y_1; σ_1, δ_1][y_2; σ_2, δ_2]. We also give partial answers to some questions posed in Zhang and Zhang [6].
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