The Islamic Golden Age, also sometimes known as the Islamic Renaissance, is traditionally dated from the 8th century to the 13th century, though some have extended it to the 15th or 16th centuries. During this period, engineers, scholars and traders in the Islamic world contributed to the arts, agriculture, economics, industry, law, literature, navigation, philosophy, sciences, and technology, both by preserving and building upon earlier traditions and by adding inventions and innovations of their own. Howard R. Turner, Science in Medieval Islam, University of Texas Press, November 1, 1997, ISBN 0-292-78149-0, pg. 270 (book cover, last page) Howard R. Turner writes: "Muslim artists and scientists, princes and laborers together created a unique culture that has directly and indirectly influenced societies on every continent."