veloping electrostatic image, developer, image forming apparatus, process for forming image, process cartridge and process for measuring porosity of tonerUS73847192 Mar 200510 Jun 2008Ricoh Company Ltd.Carrier, developer including the carrier, and image forming apparatus using the developerUS7419755 *22 Jun 20052 Sep 2008Xerox CorporationParticle having a coating that comprises polymethyl methacry