Bibliography

🔹http://answers.yahoo.com/question/index?
🔹http://www.ask.com/question/interesting-facts-about-roman-numerals
🔹www.wisegeek.com
🔹www.en.wikipedia.org/wiki/roman-numerals
🔹www.en.wikipedia.org/wiki/blown-glass
🔹www.en.wikipedia.org/wiki/roman-glass
🔹www.metmuseum.org