Book titles are generally not protected by copyright, so you will need to look to other areas of law for protection. You may, for example, be able to register your title as a trade mark. You may also be able to use passing off laws, or the Trade Practices Act or fair trading laws to prevent someone else from using your title in a way which would mislead or deceive consumers into thinking that you had authorised the use of your title for that product or service or were endorsing that product or service.