Complex sentence: Cho Oyu, Broad Peak, Gasherbrum I, Manaslu, and Makalu--all without the assistance of Sherpa guides or bottled oxygen.
Split into simpler sentences: Cho Oyu, Broad Peak, Gasherbrum I, Manaslu, and Makalu. All of his major climbs were made without the assistance of Sherpa guides or bottled oxygen.