Petrova, P. (2020). Applying a Personalized Model in PhD Student Learning. 20 International Multidisciplinary Scientific Geoconference SGEM 2020 : Conference Proceedings, 18 - 24 Aug. 2020, Albena, Bulgaria : Vol. 20. Informatics, Geoinformatics a. Remote Sensing. Iss. 2.1 (с. pp. 41-49). Sofia: STEF92 Technology Ltd..