Leonie Kramer and Nancy Keesing, academics Cecil Hadgraft and Eunice Hanger, journalist Ross Campbell and poets Ronald McCuaig, Elizabeth Riddell, A. D. Hope, R. D. Fitzgerald, Douglas Stewart, Kenneth Slessor, John Thompson, Vivian Smith and Charles Higham. In 1967 the Library reported on further progress; "The steady progress of Mrs. Hazel de Berg’s series of tape recordings and its extension from creative writers and artists to other notable Australians has brought the total number of reels to 254 and those recorded to nearly 500. A tribute to her sensitivity and the cooperation of those who have been recorded, this project has created an exceptionally rich biographical source for the future."In 1974 Graeme Powell declared that;The de Berg collection is by far the largest and the most important oral history collection in Australia and can be ranked with the great collections in America. It is particularly impressive in that for many years Mrs. de Berg built up the collection with almost no assistance and even today it remains a very personal collection. and of de Berg herself he wrote ;Mrs. de Berg is a woman of great charm whose enthusiasm for oral history is undiminished after seventeen years [to 1974] of interviewing. She is also exceptionally determined and patient and her persuasive powers have finally overcome the hesitancy of a number of men whose shyness or irascibility was notorious.David Foster, in his book Self Portraits based on the recordings and released through the Library's distributor, Allen & Unwin, in June 1991, notes that in 1970 bibliographer and librarian Pauline Fanning, in her commentary on the collection, remarked that de Berg was not herself a scholar of literature so "is not sufficiently well informed to know what questions to ask, and furthermore, she has so edited the tapes as to eliminate the questions she asks. This results in the recording being in monologue form, with no indication as to why or how the person interviewed was prompted to speak on a particular topic." In response Foster argues that de Berg's "idiosyncratic approach in fact creates rather fewer difficulties with writers than with politicians [...] since writers may be judged by what they have said and written, and perhaps ought to be, it does little harm, I believe, to let them ramble on to their hearts' content, as a great many of them did." De Berg's interviews continue to be cited in books,