Ottilie Nitzsche kept track of the photographs she took by keeping an index book in alphabetical order. For example if she took a picture of Mr. Smuts, it was entered under S in the log book, and then under the year it was taken. There are 4 volumes: Volume 1 from 1940 to 1946 ,Volume 2 from 1947 to 1950, Volume 3 from 1951 to 1953, Volume 4 from 1954 to 1956,Volume 5 from 1957 to 1957, and Volume 6 from 1961 to 1961.

All this information can be accessed on the Digital Namibian Archives compiled by NUST