Original sentence: He shared the Gurdjieff system for 25 years in England and the United States, having separated from Gurdjieff in 1924 personally, for reasons he explains in the last chapter of his book In Search of the Miraculous
Edited sentence: He shared the (Gurdjieff) "system" for 25 years in England and the United States, having separated from Gurdjieff in 1924 personally, for reasons he explains in the last chapter of his book In Search of the Miraculous