HP 56/57 Combo Pack - 2-pack - black, color (cyan, magenta, yellow) - original - ink cartridge - for Deskjet 51XX; Officejet 41XX, 42XX; Photosmart 7150, 73XX, 7550; psc 1110, 12XX, 13XX - Walmart.com
Amazon.com: DoorStepInk Remanufactured in The USA Ink Cartridge Replacements for HP 56 & 57 C9321BN C6656AN C6657AN Black and Tri-Color Combo Pack for Use with Deskjet, Photosmart, PSC Printers : Office Products
HP 56 57 Ink Cartridge Combo Pack of 5 - HP 56 and 57 @ $62.95