1. Gibilisco, Stan and Neal Slater. Encyclopedia of Electronics. 2nd ed. TPR Book, Summit, PA: 1990. Pp. 897-898.

2. Lanzendorf, Peter. The Video Taping Handbook. Harmony Books: 1981. Pp. 12-25.

3. Parker, Sybil. McGrath Hill Encyclopedia of electronics and computers. McGrath Hill Book Co.: 1982. Pp. 483.

4. Utz, Peter. Today's Video equipment, setup and production. Prentice Hall Inc.: 1987. Pp. 61-65.

5. http://www. gulker.com/ra/vhsbeta.html

6. http://www.e-town.com/news/articles/firstvhs100197swa.html