Complex sentence: These accusations were formally levied by the sociologist, Julius Rubin, who wrote a book on the subject after interviewing ex-members and researching Bruderhof history although he never visited a working Bruderhof and did not contact any current members during his research.
Split into simpler sentences: These accusations were formally levied by the sociologist, Julius Rubin, who wrote a book on the subject after interviewing ex-members and researching Bruderhof history. It must be noted that he had never visited a working Bruderhof and had not contacted any current members during his research.