Errata In the list of patents which expired on April 30, 1995, due to failure to pay maintenance fees, in the OG of July 11, 1995, Patent Number 4,660,568, should not have appeared since the fee was timely paid. In the list of patents which expired on June 15, 1997, due to failure to pay maintenance fees, in the OG of August 26, 1997, Patent Number 5,218,757, should not have appeared since the fee was timely paid. In the list of patents which expired on September 27, 1998, due to failure to pay maintenance fees, in the OG of December 8, 1998, Patent Number 5,350,744, should not have appeared since the fee was timely paid. In the list of patents which expired on January 10, 1999, due to failure to pay maintenance fees, in the OG of March 23, 1999, Patent Number 5,379,859, should not have appeared since the fee was timely paid.