Just so you know however, it is well established that we had a very large native population before European settlers arrived, and it's well established that smallpox killed a lot of people. The research here demonstrates that the numbers may be even higher than previously thought.

As for the papers, there are two.

The first argues the case for the recorded smallpox in early settler years to have arrived with the boatloads of people from the UK who are known to have had smallpox, rather than have arrived in Sydney all the way across the continent from pre-colonial Makassan (Indonesian) trade along the northern coast (which would be a difficult path). It doesn't consider the case of vectoring from Dutch survivors of Western Australian spice trade wrecks (which is also an unlikely and difficult path).

~ https://www.researchsquare.com/article/rs-5683492/v1

The second has a crack at estimating pre colonial population size:

   Robust estimates of the population dynamics of pre-colonial Indigenous Australians are poor due to lethal diseases, frontier violence, and no systematic censuses.
  We review ethnographic observations, archaeological and genetic reconstructions, and modelled carrying capacity, to infer Indigenous population size prior to colonial invasion.

and on the face of it has a more reasoned and methodological approach than typical seen in the journals of right wing bigots, eg: Quadrant - https://en.wikipedia.org/wiki/Quadrant_(magazine) which rather famously did similar work by "feels".