Fewer articles were found for the earlier years in this time period in the database used (zero for 1970, one for 1969, 1971 for example). A full scale corpus was still able to be created and can be analyzed with the various Voyant tools in this post. Here are a few useful summaries describing the documents, their contents and their most common words in a plain format.
Note: the “(no abstracts)” documents are marked to indicate that the article information obtained only contained titles and keywords but no abstracts. It was unclear why some of the articles did not have their abstracts downloaded with them.
Below, a few more tools can be found for some interesting visualization of the 1969-79 corpus:
More information on Voyant Tools can be found here