San-speaking peoples do not constitute an ethnic group in the usual sense. The most widely known are those who call themselves "Zhu I oasi" (!Kung or Juwasi in most ethnographies), although the other peoples mentioned above have also been extensively described; about ten other groups have been well studied by linguists. In Botswana, all these peoples are called collectively "Basarwa," and this term is often seen in recent ethnographic literature. An estimated 30,000 San-speaking peoples lived in Botswana, about 12,000 in Namibia, and about 8,000 in Angola. San-speaking peoples have long been famed for beadwork, both of ostrich-eggshell beads, which they manufacture, and of glass beads, which they purchase or obtain in trade. They are widely believed to be responsible for the fine rock paintings of southern Africa. Recently three men (two Zhu I oasi and one Nharo) have gained recognition as watercolorists; in 1980 one of them received a prize at the Botswana National Art Show.