Book : Oswald Watt. A tribute to his memory by a few of his friends.
Author : Edited by Sydney Ure Smith, Bertram Stevens, & Ernest Watt
Published : 1921.
Publisher : Art in Australia, Sydney.
Comments : 70 pages including photographs. Hard to find and hence expensive, usually goes for between $100AUD to $300AUD.
Availability : Out of print.
Seller : Antique Bookstores.

Book : The Official History of Australia in the War of 1914 - 1918, Volume VIII. The Australian Flying Corps.
Author : F.M Cutlack.
Published : 1923, 1984.
Publisher : University of Queensland Press, St Lucia, Queensland.
Comments : References Oswald Watt on pages, 69, 35, 175, 178. Biography and estimate of p 41-42. Quoted 176n.
Availability : In print.
Seller : Australian War Memorial and Australian War Memorial Gift Shop.

Book : ANZACs over England
Author : David Goodland and Alan Vaughan
Published : 1992
Publisher : Alan Sutton Publishing Ltd. GB.
Comments : biography, Chapter 4, pages 56 - 63. Numerous other mentions throughout the book.
Availability : In print.
Seller : Cross and Cockade.