bloop bloor blorb blorp blurb blurr bo-bo bobr bobup boll- bollo bollu booru borbo boro- boroo borou borro borul borup boul- boulo brobo broll brolo brool brrrr brull bulb- bull- bulou bulul burol buroo burro burru l-pop lobbo lobo- lobor lollo lolol loobu lopou lorup louro lubur lulul lupul lurup o-r-b obolo oboro ollup ollur olour ooooo oploo opobo oppol orlop orobo orolu oruro oullo ouoro ourol ploop plopp plopu plupp po-po polbo pollo pollu polop polur poopo poplr popop poppo popup poro- porro porur poulp probo proll prolo proor prop- propl propp propr pubo- pull- pullu puppo puro- purul ro-ro robbo robo- robop robor robur rollo rorbu roull rprop rubor rubup rullo u-pop ubobo ullur uloop ulpur ululu uluru upolo upolu uroob urour urubu uuuuu