Complex sentence: New English Library titles were particularly popular in the early 1970s, when hack writers were hired to work under names such as Richard Allen and Mick Norman to churn out tales of Hells Angels and skinheads.
Split into simpler sentences: New English Library titles were particularly popular in the early 1970s. Hack writers were hired to work under names such as Richard Allen and Mick Norman to churn out tales of Hells Angels and skinheads.