O'Callaghan, John P.
Nationality: Undetermined, possibly 
(United States)
Identities and Authority Control
- Open Library: OL2446686A
- pdbooks.info ID: 53237
John P. O'Callaghan Contributed to the Following:
| Title | Edition | Year of Publication | Role | Country of Publication | Possible Copyright Status | Available Online? | |||
|---|---|---|---|---|---|---|---|---|---|
|  |  | 
| ||||||
| Amateur enlarging | 1928 | Author | |  | |  | | ||