However, once he started painting, Ritter began his most prolific period.

It's been the most prolific period in my writing life.

Although his most prolific period was in the late 1960s, he still continues to paint.

The 1920s saw a very prolific period in Kelly's career.

His most prolific period was from the 1970s through the 1980s.

His most prolific period was from the 1960s to the early 1980s.

This marked the beginning of his most prolific period as an author.

The 1950s and 1960s are known as his most prolific artistic period.

The 1970s was Stanley's most prolific period of film making.

This was to be his most prolific period as an artist.