Billabong is a 10-book series with 10 primary works first released in 1910 with contributions by Mary Grant Bruce.
1910 • 4 Readers • 244 pages • 3.5
1912 • 1 Reader • 223 pages • 4
1913 • 1 Reader • 270 pages • 4
1914 • 2 Readers • 316 pages • 2
1916 • 2 Readers • 262 pages • 2
1919 • 1 Reader • 334 pages • 2
1921 • 1 Reader • 200 pages • 3
1924 • 1 Reader • 3
1931 • 1 Reader • 286 pages • 2
1942 • 1 Reader