▁the ▁relationships ▁between ▁soci opol it ical ▁structures , ▁administrative ▁inter ferences , ▁and ▁land ▁ten ure . ▁▁ ▁His ▁field work ▁concentr ated ▁on ▁the ▁L ega , ▁B em be , ▁Z y oba ▁and ▁Ny anga ▁pe op les . B ie bu y ck ▁was ▁initi ated ▁to ▁the ▁various ▁gr ades ▁of ▁the ▁B w ami ▁init iation ▁of ▁the ▁L ega . ▁ ▁Field work ▁▁▁ 1 9 5 7 ▁– ▁ 1 9 6 1 ▁▁▁ ▁Inter mitt ent ▁brief ▁periods ▁of ▁field work ▁among ▁some ▁fifty ▁different ▁Congo ▁populations , ▁including ▁Z ande , ▁Ag bar am bo , ▁Mang bet u , ▁Male le , ▁Mang be le , ▁May ogo , ▁Me eg ye , ▁Mam vu , ▁B wa , ▁Y ew , ▁M ab in za ▁( N gom be ), ▁Mong el ima ▁( B abor o ), ▁B ira , ▁L ese , ▁Tal ing a , ▁M b uba , ▁L end u , ▁Al uur , ▁Le ka , ▁Pere , ▁Kom o , ▁Hav u , ▁N ande , ▁Tem bo , ▁H unde , ▁V ira , ▁Ful iro ▁( F ul ero ), ▁Sh i , ▁L uba - K as ai , ▁K ongo - B av ung ani , ▁K ongo - N t and u , ▁Te ke - M fin u , ▁Wu um , ▁Mongo ▁( E k ota ▁and ▁Bak ut u ), ▁Ye ke , ▁S anga