In my opinion I would make this one book that you do not add to your collection; don't attempt to obtain it. No matter what your reason may be, given the current climate and the Governments stance toward these sorts of issues, I don't think it's particularly wise to attempt to posses a book that guides you on making explosives and similar subject matter.
As Rod has pointed out the book has been refused classification:
View Title | Australian Classification
I've never looked into this specific book, but in regard to possessing it, it would likely vary state by state, albeit slightly. However given it's status one could assume that you'd have to import it into the country in order to obtain a copy. Importing it would likely give rise to an offence under the relevant Customs Act/Regs etc. Further, if found to be in possession of it, depending on the context and background in which it was discovered, it could cause some big problems for you, given it's subject matter - Think charges, terrorism investigation and being held for an extended period of time without charge etc.