“…Ore extensions of injective type are strictly contained in skew PBW extensions (this is not possible for original PBW extensions; see [32], for a list of noncommutative rings which are skew PBW extensions but not iterated Ore extensions). Several ring and module theoretical properties of skew PBW extensions have been established by different people (e.g., Acosta [1], Artamonov [4], Hamidizadeh et al [15], Hashemi et al [17], [18], [19], Lezama et al [14], [22], [27], [28], [29], [30], [31], [32], [33], Louzari [35], Niño et al [39], [40], Tumwesigye et al [54], Zambrano [55], and the authors [49], [50], [52], [53]). A book containing research results about these extensions has recently been published (see Fajardo et al [11]).…”