@article{schwerdtfeger_1958, 
  title={On the discriminant $xsp{prime} Axcdot ysp{prime} Ay- (xcprime Ay)sp{2}$}, 
  DOI={10.4153/cmb-1958-018-0}, 
  publisher={Canadian Mathematical Society}, 
  author={Schwerdtfeger}, 
  year={1958}, 
  month={Jan}
  }