bfrog bo-bo bobr bobup boffo bogof bogor bogu bogur booru borbo borgo borgu boro- boroo borou borro borup bourg brobo brrrr bruff brugg buffo bugoo burgo burgu buroo burro burru fogbo foggo fogou fogup forgo forro forur fougo fourb fourg fouro froop froup frugo fu-fu fugro fugug furbo furo- furor go-go go-oo go-op gobbo gofor gofup gogro goobo gooff gopro gorgo gprof grgur groff grogg groof groop gropp grouf group grrrr grubb gruff gubbo gubru guroo gurro gurur o-r-b oboro offof ofour ofpop ogogo ogugu ooooo opobo orfor orobo orrgo oruro ouoro pforp po-po poopo popop poppo popup porgo poro- porog porro porur pouff probo proff progg proof proor prop- propp propr pubo- puppo puro- ro-ro robbo robo- robop robor robur rofor rogfp rorbu rprop rubof rubor rubup ruffo rufo- u-pop ubobo ufofu uforb ugoff ugro- ugrug upfor upoff uroob urour urubu uuuuu