To provide a precise reference for Hartley and Bertola in the context of Western Australia mining, I'll need more specific details about the work you are referring to, such as the title of the paper, the year of publication, or any other pertinent information.
However, if you are looking for a general way to cite works by Hartley and Bertola from this field, here’s an example format you might use, adapting it to the details of the actual work:
APA Style: Hartley, P., & Bertola, A. (Year). Title of the work. Publisher. [or Journal Name, Volume(Issue), Page range. DOI/URL if applicable]
MLA Style: Hartley, P., and A. Bertola. Title of the Work. Publisher, Year.
If you can provide more details, I would be able to help you create a more specific reference.