Peter Wang, Robert Hunt, Jeff McGriff and Elkins, Richard E. 2006. The Grammar of Matigsalug Manobo. Manila: SIL Philippines. (Online: \url{https://www.sil.org/resources/archives/53940}, accessed 23 December 2023).
@book{bonmannsymmetrical-wang2006matigsalug,
address = {Manila},
author = {Peter Wang, Robert Hunt, Jeff McGriff and Elkins, Richard E.},
note = {Online: \url{https://www.sil.org/resources/archives/53940}, accessed 23 December 2023},
publisher = {SIL Philippines},
title = {The Grammar of Matigsalug Manobo},
year = {2006}
}