![[William Wheeler Hubbell, authorized to apply for patents.]](https://covers.openlibrary.org/b/id/10200621-M.jpg)
United States. Congress. Senate. Committee on Patents
Kokuritsu Kokkai Toshokan (Japan)
Canada
United States. General Accounting Office
Fujian Sheng di fang zhi bian zuan wei yuan hui
Qinghai Sheng di fang zhi bian zuan wei yuan hui