I've found that, in general, these Australian books are somewhat tough to track down. The oddest part is there's conflicting information from people in Australia about them. The majority of those I've talked to have told me there's no real interest in them from collectors, they're looked at with the indigenous bias that seems to plague many foreign published books and are considered to have virtually no value whatsoever. However Tony (solarcadet) seems to keep getting the opposite story, that the local collectors won't generally let go of them and that many of the key books are expensive and highly sought after. I don't know for sure which story is true but I've been lucky enough to be able to pry these loose over the last couple of years.