I am trying to find out more information about: Gilbert BERKMAN - born abt 1937 in Austria. His name is listed as Gilbert BIRKMAN born abt 1839. Source Publication 1823-19 Source: ELLIOTT, BRUCE S. Index to the 1871 Census of Ontario: Leeds, Grenville, Toronto: Ontario Genealogical Society, 1990.268p Page 17. How can I can this information about my Great Great father Gilbert Berkman (Birkman)

Locate the source. You've got the title "1871 Census of Ontario: Leeds, Grenville", the author "ELLIOTT, BRUCE S.", the publisher "Toronto: Ontario Genealogical Society, 1990." and even the page number the information is on "Page 17".

This index can be purchased from the Ontario Genealogical Society but it can also be searched online at Library & Archives Canada, Queen's University and Family Search

The entire 1871 census (images included) is available through an Ancestry subscription.