During her time researching the life and work of Helen Adam, Prevallet interviewed numerous people with personal and professional connections to Adam or the literary movements she was a part of. Series III contains written correspondence between Prevallet and these figures.

In some noted instances, the title of the folder corresponds to the subject of the correspondence or copies of correspondence between the person and Helen Adam.

The James Laughlin Collection contains typescripts and autograph manuscripts, many with corrections, for approximately 835 poems; and 39 letters from Laughlin to individuals such as Charles D. Abbott, Peter Russell, and Robert Bertholf.