Complex sentence: Röthlisberger produced two important monographs when at CRREL; one on seismic properties of ice Röthlisberger, H.1972, Seismic exploration in cold regions.
Split into simpler sentences: Röthlisberger produced two important monographs when at CRREL. One on seismic properties of ice Röthlisberger, H.1972, Seismic exploration in cold regions.