Helwich, Othmar
Nationality: Undetermined, possibly 
(Unknown (outside United States))
Identities and Authority Control
- pdbooks.info ID: 104770
Othmar Helwich Contributed to the Following:
| Title | Edition | Year of Publication | Role | Country of Publication | Possible Copyright Status | Available Online? | |||
|---|---|---|---|---|---|---|---|---|---|
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| Die infrarot-fotografie und ihre anwendungsgebiete | 1937 | Author | |  |  | | | ||