Complex sentence: This was the only book that O'Mahony wrote for the New Adventures, however in July 1994 Virgin began publishing the Missing Adventures, and O'Mahony pitched a novel for this series and was accepted.
Split into simpler sentences: This was the only book that O'Mahony wrote for the New Adventures. However in July 1994 Virgin began publishing the Missing Adventures, and O'Mahony pitched a novel for this series and was accepted.