Cambridge, Ada. 1844-1926
Thirty years in Australia / Ada Cambridge
New South Wales University Press, 1989
 Buku Teks
Hu, Chiao-Mu
Thirty years of the communist party of China
Foreign Languages Press, 1952
 Buku Teks
China and New Zealand : a thriving relationship thirty years on
edited by James Kember
New Zealand Asia Institute, 2003
 Buku Teks
Rob, Golding
Mini thirty-five years on/Rob Golding
The Bath Press, Avon, 1994
 Buku Teks
Statistics of centuries : statistical curios in Hungarian history
The Hungarian Central Statistical, 2002
 Buku Teks