The authors give a definition of Morrey spaces for nonhomogeneous metric measure spaces and investigate the boundedness of some classical operators including maximal operator, fractional integral operator, and Marcinkiewicz integral operators.
"Morrey Spaces for Nonhomogeneous Metric Measure Spaces." Abstr. Appl. Anal. 2013 (SI26) 1 - 8, 2013. https://doi.org/10.1155/2013/196459