Source: https://www.researchgate.net/profile/Isaac_Agyei4/publication/343629253_Design_and_Fabrication_of_Metal_Key_Holders_and_Cufflinks_as_Souvenirs_for_Kwame_Nkrumah_University_of_Science_and_Technology_Kumasi_Ghana/links/5f36c8b7458515b7291f4970/Design-and-Fabrication-of-Metal-Key-Holders-and-Cufflinks-as-Souvenirs-for-Kwame-Nkrumah-University-of-Science-and-Technology-Kumasi-Ghana.pdf