AustLII (Australian legislation and cases)
Scaleplus (Australian Federal legislation)
On AustLII, you can do a search within the linked documents by inserting phrases into the search box at the top of the web page. If you are looking for a phrase, type the phrase in the text box and then select "this phrase" from the drop down box immediately above the text box. If you are looking for documents that contain the words, but not in any specific order and not necessarily next to each other, then type the words in the text box and select "all of these words" from the drop down list.