ADU-TWUMWAAH, Deborah. Market Structure, Technological Spillover and Productivity in Ghana. International Journal of Sciences: Basic and Applied Research (IJSBAR), Jordan, v. 13, n. 2, p. 172–182, 2014. Disponível em: https://www.gssrr.org/JournalOfBasicAndApplied/article/view/2763. Acesso em: 15 dec. 2025.