Lécuyer argues that Silicon Valley's emergence and its growth were made possible by the development of unique competencies in manufacturing, in product engineering, and in management. Entrepreneurs learned to integrate invention, design, manufacturing, and sales logistics, and they developed incentives to attract and retain a skilled and motivated workforce. The largest Silicon Valley firms—including Eitel-McCullough (Eimac), Litton Industries, Varian Associates, Fairchild Semiconductor, and Intel—dominated the American markets for advanced tubes and semiconductors and, because of their innovations in manufacturing, design, and management, served as models and incubators for other electronics ventures in the area.