If you can go to Marleybone, I think that is the best place to get them. In regents square you can find 2 to 3 in the fountain. in digmore station, find 2 to 3 in the fountain. If you go to hyde park, use the teleport to the hub, turn around, go up the stairs all the way to the end and you will find up to 4 places next to the fountain. There is always at least one (maybe more) at the fountain of barkingham palace. Change realms and try again.