Yotov, K., S. Hadzhikoleva, E. Hadzhikolev, D. Orozova, Forecasting Electricity Consumption in a National Power System, Proceedings of the XXII-nd International Symposium on Electrical Apparatus and Technologies SIELA 2022, 1-4 June 2022, Bourgas, Bulgaria.

Terziyska, M., Yotov, K., Hadzhikolev, E., Terziyski, Zh., Hadzhikoleva, S., Forecasting Electricity Consumption with Intelligent Hybrid Model, Proceedings of the XXII-nd International Symposium on Electrical Apparatus and Technologies SIELA 2022, 1-4 June 2022, Bourgas, Bulgaria.

Hadzhikolev, E., S. Hadzhikoleva, H. Hristov, E. Yonchev, V. Tsvetkov, Modeling of Pedagogical Patterns in an E-learning System, International Journal of Emerging Technologies in Learning (iJET), 16(24), 2021, pp. 205–219.

Hadzhikoleva, S., A. Uzunov, E. Hadzhikolev and S. Cheresharov, Conceptual Model of a Quality Assurance System in Higher Education, 2022 21st International Symposium INFOTEH-JAHORINA (INFOTEH), 2022, pp. 1-6.

Hadzhikolev, E., S. Hadzhikoleva, K. Yotov, M. Borisova, Automated Assessment of Lower and Higher-Order Thinking Skills Using Artificial Intelligence Methods, In: Antovski, L., Armenski, G. (eds) ICT Innovations 2021. Digital Transformation. ICT Innovations 2021. Communications in Computer and Information Science, vol 1521. Springer, Cham, pp 13–25, Electronic ISSN: 1865-0937, Print ISSN: 1865-0929.

Hadzhikolev, E., S. Hadzhikoleva, D. Orozova, K. Yotov, A Comprehensive Approach to Assessing Higher and Lower Order Thinking Skills, In: Uncertainty and Imprecision in Decision Making and Decision Support: New Advances, Challenges, and Perspectives. IWIFSGN BOS/SOR 2020 2020. Lecture Notes in Networks and Systems, vol 338. 2022. Springer, Cham, pp 164–177, Electronic ISSN: 2367-3389, Print ISSN: 2367-3370.

Rachovski, T., S. Hadzhikoleva, E. Hadzhikolev, Angel Lengerov, Using Clean Architecture Principles to Improve the Design and Implementation of the Mobiles Online Platform, In: Shakya, S., Du, KL., Haoxiang, W. (eds) Proceedings of Second International Conference on Sustainable Expert Systems. Lecture Notes in Networks and Systems, vol 351. 2022. Springer, Singapore, pp. 11-19, Electronic ISSN: 2367-3389, Print ISSN: 2367-3370.

Yotov, K., E. Hadzhikolev, S. Hadzhikoleva, Linear Separability as a Condition for Solving Multiple Problems by a Single Threshold Neuron, In: Pandian, A.P., Fernando, X., Haoxiang, W. (eds) Computer Networks, Big Data and IoT. Lecture Notes on Data Engineering and Communications Technologies, vol 117. Springer, Singapore, 2022, pp 575–592, Electronic ISSN: 2367-4520, Print ISSN: 2367-4512.

Orozova, D., S. Hadzhikoleva, E. Hadzhikolev, A Course Gamification Model for the Development of Higher Order Thinking Skills, Proceedings of the 44th international convention on information, communication and electronic technology MIPRO 2021, pp. 1772 - 1777.

Йончев, Е., С. Хаджиколева, Mоделиране на педагогически патерни в Мудъл чрез стандартни учебни дейности и ресурси, Научни трудове на Съюза на учените в България – Пловдив. Серия В. Техника и технологии. Том XX, ISSN 1311-9419 (Print); ISSN 2534-9384 (Online), 2022, стр. 104-109.

Борисова, M., С. Хаджиколева, Сравнителен анализ на резултатите от обучението по математика в 6. клас, Научни трудове на Съюза на учените в България – Пловдив. Серия В. Техника и технологии. Том XX, ISSN 1311-9419 (Print); ISSN 2534-9384 (Online), 2022, стр. 122-125.

Yotov, K., E. Hadzhikolev, S. Hadzhikoleva, Model for Forecasting of Electricity Losses During Transmission and Distribution in an Electricity System, International Journal of Engineering Trends and Technology, Volume 69, Issue 6, pp. 93 - 98.

Rachovski, T., E. Hadzhikolev, S Hadzhikoleva, Models and Methodologies for Automated Creating of Webpage Mobile Versions, International Conference on Technics, Technologies and Education ICTTE 2020, November 4-6 2020, Yambol, Bulgaria.

Yotov, K., E. Hadzhikolev, S. Hadzhikoleva, Influence of the price of electricity for the industry on the consumption in the economic sector in Bulgaria, International Conference on Technics, Technologies and Education ICTTE 2020, November 4-6 2020, Yambol, Bulgaria.

Hadzhikolev, Е., S. Hadzhikoleva, D. Orozova, Models for Quality Assurance and Accreditation of Higher Education, Proceedings of ICERI2020 Conference, 9th-10th November 2020, pp. 6526 - 6534, ISBN: 978-84-09-24232-0.