Volume 10, Issue 1, January 2021, Pages 23-29
Maria Hristova Kazakova; Georgi Angelov Pavlov; Valentin Dichev Dichev; Kiril Kostov Simitchiev; Chavdar Stefanov Stefanov; Victoria Stepan Sarafian
Volume 2, Issue 2, August 2013, Pages 76-80
Moslem Shakeri; Atta Mahdkhah; Farid Panahi