Method for modifying conventional snow skiis to permit downhill skiing on smooth grassy slopes during non-winter periods
作者： Charles M Tyson
DOI:
关键词: Snow 、 Hydrology 、 Geology
摘要:
lens.org 参考文章(3)
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Bean George, An Improved Rink Skate. ,(1911)
Ravon Georges, Appareil de sport et de jeux ,(1936)