▁and ▁naming ▁of ▁the ▁objects ▁present ▁in ▁this ▁field ▁of ▁research ". ▁In ▁doing ▁so ▁it ▁util ised ▁a ▁classification ▁by ▁Ernst ▁S pro ck hoff , ▁which ▁in ▁turn ▁was ▁based ▁on ▁an ▁older ▁Dan ish ▁model .< ref > Er n st ▁S pro ck hoff : ▁Die ▁nord ische ▁Meg al ith k ultur , ▁ 1 9 3 8 , ▁c ited ▁in ▁Schul dt ▁ 1 9 7 2 , ▁p . ▁ 1 0 </ ref > ▁▁ ▁N aming ▁scheme ▁ ▁Schul dt ▁listed ▁six ▁types : ▁ ▁the ▁simple ▁dol men ▁( U rd ol men ) ▁the ▁extended ▁dol men ▁( er we iter te ▁Dol men ) ▁the ▁great ▁dol men ▁( G ro ß d ol men ) ▁the ▁passage ▁grave ▁( G ang gra b ) ▁the ▁long ▁bar row ▁without ▁a ▁chamber ▁( H ün en b ett ▁ohne ▁Kam mer ) ▁the ▁stone ▁c ist ▁( Ste ink iste ) ▁▁ ▁Geographic ▁distribution ▁▁ ▁As ▁part ▁of ▁a ▁joint ▁vent ure ▁between ▁the ▁Institute ▁of ▁Pre history ▁and ▁Early ▁History ▁of ▁the ▁East ▁German ▁Academy ▁of ▁Sciences ▁in ▁Berlin ▁and ▁the ▁Museum ▁of ▁Pre history ▁and ▁Early ▁History ▁at ▁Sch wer in ▁a ▁total ▁of ▁ 1 0 6 ▁of ▁ 1 1 4 5 ▁detect able ▁meg al ith ic ▁were ▁exc av ated ▁from ▁ 1 9 6 5 ▁to ▁ 1 9 7 0 ▁and ▁the ▁gra ves ▁that ▁were ▁found ▁were ▁documented ▁and ▁class ified