bibbo bibio bibri big-i bigig bigoo birgi birgu birou birur bo-bo bobbi bobr bobri bogor bogu bogur boiro booru borbo borgo borgu borio boro- boroo borou borro bourg bouri brigg brigi briou brobo brrrr brugg bruiu bruri bugoo burgi burgo burgu burio buroo burri burro burru ggobi gibbi gibi- giour girru giubo go-go go-oo gobbi gobbo gobig gobio gobir gogoi gogro gogui goibo goobi goobo gorgo gorir grgur grigg grogg grrrr grubb gruiu gubbi gubbo gubio gubru guggi gugir guiri guiro gurgi guroo gurro gurur ibbur ibibo ibogo iggri igigi iiiii ioooi ioooo iorio irobo irori irour o-r-b oboro ogiri ogogo ogugu oguri ooioo ooooo oribi origi origo orobo orrgo oruro ouigo ouir- ouoro ribbi ribo- rig-i rigio rigor ro-ro robbi robbo robo- robor robur rogoi rorbu rubbi rubio rubor rugii rugir ruiru ubirr ubobo ugro- ugrug uigur uiro uroob urour urubu ururi uuuuu