These daf yomi shiurim were given by Rav Dovid Grossman from 1985 to 1992 for the community of Los Angeles. They were later encoded to mp3 in 2003 by a volunteer for dafyomi.org, and then more volunteers helped index the recordings by daf and amud. Please note an error on Daf 9b. The audio says that the fathers witnesses have to pay the husband his kedubah. See Rashi, it means they have to pay 100 selaim that they wanted to be m'chayiv the husband to pay the father for motzei Shem Ra.