Report re Westerbork concentration camp, Holland

This collection consists of a typescript, annotated (possibly) original report into conditions at Westerbork Concentration camp, entitled Kollektive Arbeit einer Widerstandsgruppe, apparently produced by member(s) of the 'Widerstandsgruppe' a typescript copy of the same; and correspondence between the Alfred Wiener and Professor David Cohen, Amsterdam relating to the above. The associated correspondence questions the reliability of the report. The report is critical, amongst others, of Professor Cohen, who had something to with the camp, and who subsequently wrote a book about the camp.