One advantage of fluorescent bulbs is that they last very long and therefore are cost-efficient. On this light bulb you'll find a G5 socket.
From Amazon
Osram 21 Watt Lumilux T5 High Efficiency Fluorescent Lamps - white
LED Bulbs
Osram T5 Fluorescent Tube 21W 849mm 33 Inch Warm White - 591506
Big on Electricals
Osram T5 Fluorescent Tube 21W 849mm 33 Inch Warm White - 591506
Lamps 2U Direct
900mm (3ft) 15 watt T8 LED Tube Especially for Butchers