Clark, RossHalim, AmranCarrington, LoisWurm, S. A.2021-12-012021-12-01085883281XPL-C76.137http://hdl.handle.net/1885/253298application/pdf© 1982 Ross Clarkhttp://creativecommons.org/licenses/by-sa/4.0Necessary' and 'unnecessary' borrowing198210.15144/PL-C76.137 2021-12-01Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)