“…Remark 5: Note that the case when τ = σ and both are Galois automorphisms of K of order 2, the iterated construction coming from α θ (D, D) is in fact the same as the matrix representation of the crossed product (K/F, γ, θ, 1) [18] induced by left multiplication, where the automorphisms σ, τ generate the biquadratic extension K/F and D = (K/K σ , σ, γ).…”