Complex sentence: Holiday Magic, a multi-level marketing organisation founded by William Penn Patrick (- 1973) in the United States, played a role in the development of Large Group Awareness Training in the human potential movement.
Split into simpler sentences: Holiday Magic, a multi-level marketing organization founded by William Penn Patrick (- 1973) in the United States. Some claimed that Holiday Magic played a role in the development of Large Group Awareness Training in the human potential movement.