PNG ICO ICNS MORE
Business & finance
Smooth
Pretty Office
plus, Add
YellowGreen
256x256
Mixed
Basic Set
Add, substract, plus
64x64
PNG MORE
Pixel
Add, Accept, plus
24x24
Shopping & e-commerce
Woothemes Ultimate Icon Set
128x128
DRF
green, plus, Add
32x32
3D
Add
48x48