Ivan Popov
发表
Krassimir Dotchev,
I. Popov,
S. Onuh,
2010
.
Ivan Jordanov,
Apostolos Chondronasios,
I. Jordanov,
2016
.
Eric Dimla,
Sikiru Oluwarotimi Ismail,
Hom Nath Dhakal,
2017
.