✦ LIBER ✦
Echo sounding apparatus with adjustable sounding direction: Maass, G., US patent 3, 451, 038 (17 June 1969) (filed 27 July 1965) (1817)
- Publisher
- Elsevier Science
- Year
- 1970
- Tongue
- English
- Weight
- 124 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0041-624X
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