00506nam a22001577a 450000500170000002000180001710000220003524500860005726000290014330000130017249000470018550000540023265000200028665000200030670000220032620260112150617.0  a9783030164119  aColombo, Fabrizio  aQuaternionic closed operators, fractional powers and fractional diffusion process  aLondonbBirkhauserc2019  aviii+322  aOperator theory: Advances and applications  aOperator theory advances and applications Vol 274  aVector operator  aSpectral theory  aGantner, Jonathan