stated that he began manufacturing the boots in the late 1950s. Surfer Shane Stedman of Australia has stated in interviews that he invented the ugg boot. Perth sheepskin boot manufacturers Bruce and Bronwyn McDougall of Uggs-N-Rugs have manufactured the boots since the late 1970s. The origin of the term "ugg" is also unclear. Stedman registered the trademark "UGH-BOOTS" in Australia in 1971, and in 1982 registered the "UGH" trademark. Frank Mortel claims that he named his company's sheepskin boots "ugg boots" in 1958 after his wife commented that the first pair he made were "ugly." Some accounts have suggested that the term grew out of earlier variations, such as the "fug boots" worn by Royal Air Force pilots during World War I. The 1970s saw the emergence of advertising using the UGG and UGH terms both in trade names and as a generic term in Australia. The Macquarie Dictionary of the Australian language first included a definition for "ugg boot" as a generic term for sheepskin boots in its 1981 edition. (After Stedman complained to the editors of Macquarie, subsequent editions indicated that "UGH" was a trade mark.) In the 1970s, ugg boots became popular among competitive surfers. Sheepskin footwear accounts for around 10 percent of footwear production in Australia. International sales Surfing helped popularise the boots outside Australia and New Zealand. Advertisements for Australian sheepskin boots first appeared in Californian surf magazines in 1970. By the mid-1970s, several surf shops in Santa Cruz, California and the San Fernando Valley were selling a limited number of boots purchased by the shops' owners while visiting surfing events in Australia. In 1978, a Western Australian manufacturer of sheepskin boots, Country Leather, advertised outside Australia for distributors to sell its sheepskin boots, which were made from sheepskin sourced from Jackson's Tannery in Geelong, Victoria. Seeing the popularity of the boots among American surfers, Australian surfer Brian Smith, then living in Santa Monica, California, and colleague Doug Jensen bought boots from Country Leather but were unhappy with the brand and decided to register UGG as their own trademark. Family friends invested $20,000 into the new venture and the group set up Ugg Imports. Due to other business commitments, in 1979 Jensen handed over his share of the company to Smith. In 1987 Smith registered Ugg Holdings Inc. and in 1985 registered a U.S. trademark on a ram's head logo with the words "Original UGG