- Archival number: NA IA NANU, f. 16, op. 2, spr. 45
- Author: Fedot Filin
- Language of the document: russian
- Date of the document: 1963-1968
- Reproduction method: manuscript
- Quantity: 4 sheets
- Material: paper
- Description: Letters from Fedot Filin to Viktor Petrov from Moscow and Leningrad.
