Bulgaria
| Country: | Bulgaria |
| Type: | Postage stamps |
| Series: | Modern Industrial Buildings |
| Nominal: | 13 ст |
| Year: | 1976 |
| Size: | 30 x 40 mm |
| Perforation: | comb 13 x 13¼ |
Modern Industrial Buildings
 Koslodui atomic energy centre 0.06$ |  Bobaudol thermal energy plant 0.05$ |  Sviloza chemical works 0.06$ |  Devaya chemical works |
 Sestvitro dam and hydroelectric power facility 0.18$ |