-tree bbbee be-er bebel beber beebe beele beete beeut belee belep belet bellb belle belue belur belut beppe beppu berbe berel beret berle berre berru berte betee betel beter betle betre bett- bette betul beuer beule beure beute bleep bleer bleet blere blerp blete bleue bluer bluet blurb blure blurr blurt brebu breel breer breet brell brere brett breu- brrrr bruer bruet brule brull brute btr-t bubbe buber buble buell bulb- bull- bulle bulul bulut burel buret burle burru burte burtt burut buter butle butte butut ebber ebbet ebble ebell eberl ebert eblul ebull ebure eeeee eeler eepee eleet elele eleut ellel eller ellet ellul elpee elper elulu eluru elute epptb epure erbbe erber erept erere erpel errtu erte ertel erter erupt etete etree ettel etter ettle eturu euell euler eurel eurre lebel leber lebet leell leere leert lelep leleu lelle lepel leper lepet leppe lepre lept- lerer letbe letre lette letup letur leupp lubbe luber luble lubur lulle lulte lulul luper luppe lupul lurer lurue lurup lute- luter lutte p-rep pebre peebu peele peell peere peerl peert peete pelee peler pelet pelle pepee pepel peple peppe pept- pepup perel perer peret perle perre perte perur petbe peter petr- petre petru pette petur peule peure plebe pleep pleet plete pleut plupp plut- plute prell prelp prepl prete prute pter- ptere ptprb ptpre ptprr ptprt ptpru puber puble puett puler pull- pulle pullu pulut pupet puple puppe puree purel purer purle purre purte purul puter putre putt- putte puttu putup re-up rebbe rebel reber rebet rebut reepe reere relee relet relte relue repel repet reple reppe reprt repub reput rere- reree reret retee retel reter rette reuel reuer reuet reule reute rubee rubel ruber ruble rubup ruele ruell ruere ruete ruler rupee rupel ruper ruter rutle rutte rutul ruule ruutu tbtbt tbutt teber tebet teele teell teepe teeup tele- telep teler teleu tell- telle tepee tepet tepeu teppu teret tereu terre tert- tetel teter tetle tetr- tette tlell tlett tllbr tpler treer treet trele trepp trept trere trete trett treut trubu truel truer trule trull trupt trute ttttt tuber tubul tuell tuelt tulet tulle tupee tuple turbe turbt turel turet turle turre turtu turul turup turut tutee tutel tutle tutte tuuru ubble uber- ullet ullur ulpur ultre ululu uluru upeet upper upput upter urelu urtel urter urtlu urubu urupe urutu uter- utter uttur utube uturu uuuuu