b-r-k bbook bo-bo bobko bobok bobr bogor bogu bogur bokko bokok bokor booko booru borbo borgo borgu borko borku boro- borok boroo borou borro bouko bourg brobo brook brouk brrrr brugg bugok bugoo bukk- bukor burgk burgo burgu buroo burro burru buruk gboko go-go go-oo gobbo gogok gogro goobo gorgo grgur grogg grokk grook grrrr grubb gubbo gubru gukgo gurko guroo gurro gurur k-rob ko-ko kobru kobuk kogro kokko kokor kokou kokur koogu kooru korbo korgu korku koror korro koruk kubok kugur kukko kukok kukur kurbu kurgo kurku kuruk o-r-b oboro obrok ogogo ogugu okkur okobo okoro okrog okrug okubo okuku okuru ooooo orobo orrgo oruku oruro ouoro ro-ro robbo robo- robor robur rokkk rorbu rouko rubor ubobo ugro- ugrug ukobu ukuug uroob urour urubu uuork uuuuu