Australian Mathematical Olympiads 1979-1995 (Enrichment Series, 12):

This book is a complete collection of all Australian Mathematical Olympiad papers from the first paper in 1979 to 1995. Solutions to all of the problems are included and in a number of cases, alternative solutions are also offered.

to download follow the link below:

http://rapidshare.com/files/232054883/IMO_1986-1999_0883858118.djvu