* Irene Sabadini, Michael Shapiro & Frank Sommen, editors (2009) "Hypercomplex Analysis and Applications" Birkhauser ISBN 978-3-7643-9892-7 .
* Irene Sabadini, Michael Shapiro & Frank Sommen, editors (2009) "Hypercomplex Analysis and Applications" Birkhauser ISBN 978-3-7643-9892-7 .