Dr Cowmeadow says the people who were running the centre would then have been able to choose the books they wanted to stock for the next period. She says the books would then have been changed over and the vans would go back out. They would refresh their stock and start the process again. Dr Cowmeadow says: "It's not quite the way a mobile van would work today, with people approaching the van, but it did give whoever was working there the opportunity to choose the titles that they knew their readership would like." The early mobile libraries covered large geographical areas.