1. Alexieva C, Kiryakov K (1982) Profesionalna pathologiya (Professional pathology, in Bulgarian). Medicina i Fizkultura, Sofia, pp 33–74
2. Belomitzeva L (1978) The spread of chronic bronchitis among workers in petrochemical manufacture (in Russian). Gig Tr Prof Zabol 10:5–9
3. Dimov D (1975) State of the olfactory function in some chemical intoxications. Hig Zdraveopazvane 1:30–34
4. Dimov D (1984) Vkus i obonyanie (Taste and smell, in Bulgarian). Bulgarian Medicina i Fizkultura, Sofia, pp 96–99
5. Dimov D, Raykov Hr (1971) Bulgarian olfactometer (in Bulgarian). Otorinola-ringologiya (Sofia) 3:142