What is the version of the following sentence with correct punctuation?

The nonoverlapping spectral band for carbon dioxide was not discovered until about the early 1950s For more on the history of the role of carbon dioxide in global warming see CO2 History
The non-overlapping spectral band for carbon dioxide was not discovered until about the early 1950's. For more on the history of the role of carbon dioxide in global warming see CO2 History.