Feit Electric 13-Watt Equivalent PL CFLNI Quad Tube 2-Pin GX23-2 Base Compact Fluorescent CFL Light Bulb, Cool White 4100K (1-Bulb) BPPLD13/41/HDRP - The Home Depot
120V 18w 4-Pin Twin Tube Warm White Compact Fluorescent Light Bulb - CFT18W/4P/827 (S8333) by Satco
Circle (2 Pack) PL-13W 827, 2 Pin GX23, 13 Watt Single U-Shaped Twin Tube, Compact Fluorescent Light Bulb, Replaces Philips PLS13W27 GX23 and Sylvania CF13DS827 GX23 - Amazon.com
Feit Electric 18-Watt Equivalent PL CFLNI Quad Tube 4-Pin G24Q-2 Base Compact Fluorescent CFL Light Bulb, Soft White 2700K (1-Bulb) BPPLD18E/HDRP - The Home Depot