Purchase a leather bound hard cover copy from Abe Books US$49.27 (17.9.2023)
“The annotated constitution of the Australian Commonwealth”
PLEASE-NOTE: This is a small version of the original Constitution and is only 287 pages, not 1064.

Commonwealth of Australia Constitution Act 1900 (UK) (UK Government legislation website)
ConstitutionUKEnactedpga_19000012_en (pdf as enacted)

Commonwealth of Australia Constitution Act  (current, includes s51 (xxiiiA)
Commonwealth-of-Australia-Constitution-Act (pdf)

If you are using these State Constitutions as references please check you are using the latest (current) version.

New South Wales Constitution Act 1902 (URL)

Queensland Constitution Act 1867 (URL)

South Australian Constitution Act 1934 (URL)

Tasmania Constitution Act 1934 (URL pdf)

Victorian Constitution Act 1975 (URL)
VictorianConstitutionAct75-8750a223 (docx)

Western Australia Constitution Act 1889 (URL)
Constitution Act 1889 – [06-g0-00] (pdf)