Complex sentence: One of Coren's most successful books was "The Collected Bulletins of Idi Amin", a collection of his "Punch" articles regarding Amin and was rejected for publication in the United States on the grounds of racial sensitivity.
Split into simpler sentences: One of Coren's most successful books was "The Collected Bulletins of Idi Amin". This was a collection of his "Punch" articles regarding Amin and was rejected for publication in the United States on the grounds of racial sensitivity.