Azpen, Q.; Baharudin, H.; Sulaiman, S.; Mustapha, F. (2018). Effect of process parameters on the surface roughness of aluminum alloy AA 6061-T6 sheets in frictional stir incremental forming, Advances in Production Engineering & Management, Vol. 13, No. 4, 405-416, https://doi.org/10.14743/apem2018.4.299