@MISC{QUATERNI.MIZ,
  AUTHOR = {Liang, Xiquan and Ge, Fuguo},
  TITLE = {The Quaternion Numbers},
  DAY = {14},
  MONTH = {November},
  YEAR = {2006},
  ADDRESS1 = {Qingdao University of Science\\and Technology\\China},
  ADDRESS2 = {Qingdao University of Science\\and Technology\\China},
  SUMMARY = {In this article, we define the set $\Bbb H$ of 
   quaternion numbers as the set of all ordered sequences 
   $q =\langle x,y,w,z\rangle$ where $x$,$y$,$w$ and $z$ are real numbers.
   The addition, difference and multiplication of the quaternion numbers 
   are also defined.
   We define the real and imaginary parts of $q$ and denote this 
   by $x = \Re(q)$, $y = \Im_1(q)$, $w = \Im_2(q)$, $z = \Im_3(q)$.
   We define the addition, difference, multiplication again and denote 
   this operation by real and three imaginary parts. We define the 
   conjugate of $q$ denoted by $q*'$ and the absolute value of $q$ 
   denoted by $|q|$. We also give some properties of quaternion numbers.}}

