%0 Journal Article %A Roberto Bramati %A Valentina Casarino %A Paolo Ciatti %T On the norms of quaternionic harmonic projection operators %J Comptes Rendus. Mathématique %D 2018 %P 482-488 %V 356 %N 5 %I Elsevier %R 10.1016/j.crma.2018.03.011 %G en %F CRMATH_2018__356_5_482_0