Simply Conserve G24Q/GX24Q horizontal PL 12-Watt EQ Single tube Cool White GX24Q-4 Pin Base LED Light Bulb (20-Pack) in the General Purpose Light Bulbs department at Lowes.com
Feit Electric 13-Watt Equivalent PL CFLNI Quad Tube 4-Pin G24Q-1 Base Compact Fluorescent CFL Light Bulb, Cool White 4100K (1-Bulb) BPPLD13E/41/HDRP - The Home Depot
LED PL Retrofit Lamp for 2 Pin CFL Bulbs - Replaces 18-26 Watt- G24D Base Lamps -
Philips 32W 4 Pin GX24q3 Neutral White Long Triple Twin Tube CFL Bulb | PL-T 32W/35/4P/ALTO (4-Pin) | Bulbs.com
Feit Electric 26-Watt Equivalent PL Tritube CFLNI 4-Pin Plug-In GX24Q-3 Base CFL Replacement LED Light Bulb, Cool White 4100K (1-Bulb) BPPLT26E841LEDG2HDRP - The Home Depot
LED PL Retrofit Lamp for 2 or 4 Pin CFL Bulbs - Replaces 13-18 Watt- G24d / GX24d & G24q / GX24q Base Lamps - Magnetic Ballast Compatible or Bypass, 4000K and 560 Lumens