Smith, V. C., Pearce, N. J. G., Matthews, N. E., Westgate, J. A., Petraglia, M. D., Haslam, M., et al. (2011).
Geochemical fingerprinting of the widespread Toba tephra using biotite compositions. Quaternary International,
246, 97-104. doi:10.1016/j.quaint.2011.05.012.