de Coning, E; Adam B F; Goliger A M; van Wyk T (October 2013). "An F3 tornado in Heidelerg, South Africa". National Weather Association. Weather Forecasting Research Group. Archived from the original on 29 October 2013. Retrieved 9 October 2013.
de Coning, E; Adam B F; Goliger A M; van Wyk T (October 2013). "An F3 tornado in Heidelerg, South Africa". National Weather Association. Weather Forecasting Research Group. Archived from the original on 29 October 2013. Retrieved 9 October 2013.