Author:
Pavlov Kaloyan,Genov Jordan,Mitova Rumyana,Vladimirov Borislav,Sotirov Dobromir,Taneva Gergana,Boeva Irina,Hristova Rumyana,Komitova Teodora,Gerdzhikova Klimentina,Getsov Plamen,Terziev Ivan,Grigorov Nikola
Publisher
"Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences