EPU (Economic Planning Unit) (2015) Pembangunan Wilayah.
http://www.epu.gov.my/faq%3Bjsessionid%3D988507AC669866A2D636A90D241A4A76%3Fp_p_id%
3D56_INSTANCE_xU3W%26p_p_lifecycle%3D0%26p_p_state%3Dnormal%26p_p_mode%3Dview%
26p_p_col_id%3Dcolumn-4%26p_p_col_count%3D1%26page%3D8

has been cited by the following article: