Complex sentence: The City of Montreal's official website states that the facility was built in 1930, while a 1951 "Montreal Gazette" article states that the natatorium was "first thought of back in 1939," and completed as two open-air pools in 1941.
Split into simpler sentences: The City of Montreal's official website states that the facility was built in 1930. However, a 1951 "Montreal Gazette" article states that the natatorium was "first thought of back in 1939," and completed as two open-air pools in 1941.