@book{AM,
  title = {Ars Magna, The Great Art or the Rules of Algebra},
  author = {Gerolamo Cardano},
  year = 1545,
  note = {\url{https://en.wikipedia.org/wiki/Ars_Magna_(Cardano_book)}}
}
  
@article{Algebraic_Numbers-AFP,
  author  = {René Thiemann and Akihisa Yamada and Sebastiaan Joosten},
  title   = {Algebraic Numbers in {I}sabelle/{HOL}},
  journal = {Archive of Formal Proofs},
  month   = dec,
  year    = 2015,
  note    = {\url{https://isa-afp.org/entries/Algebraic_Numbers.html},
            Formal proof development},
  ISSN    = {2150-914x},
}
