Amir  Kamal Amir, Andi  Galsan Mahie, Nur  Erawaty, Mawardi  Bahri, Devvy  A, 
    The Center of Skew Polynomial Ring over a Couple of Quaternions,
    Agricultural Journal,
    Volume 15,Issue 1,
    2020,
    Pages 7-12,
    ISSN 1816-9155,
    aj.2020.7.12,
    (https://makhillpublications.co/view-article.php?doi=aj.2020.7.12)
    Abstract: Let, R be a ring and σ is an endomorphism for
R. With multiplication rule xa = σ(a)x for all a∈R, the set
of polynomials a<sub>0</sub>+a<sub>1</sub>x+, ..., +a<sub>n</sub>x<sup>n</sup> where a<sub>i</sub>&isin;R, forms a
ring. The ring is called skew polynomial ring. This ring is
non-commutative due to the multiplication rule.
    Keywords: Center;polynomial;quaternion;commutative;multiplication rule