The following articles have been published: Regular and Totally Regular Interval Valued Neutrosophic Hypergraphs; Isomorphism of Single Valued Neutrosophic Hypergraphs; Isomorphism of Interval Valued Neutrosophic Hypergraphs; An Isolated Interval Valued Neutrosophic Graphs; Isomorphism of Bipolar Single Valued Neutrosophic Hypergraphs; Subtraction and Division of Neutrosophic Numbers; Rough Neutrosophic Hyper-complex set and its Application to Multi-Attribute Decision Making.

This is the third volume of the Encyclopedia of Neutrosophic Researchers, edited from materials offered by the authors who responded to the editor’s invitation. The authors are listed alphabetically. The introduction contains a short history of neutrosophics, together with links to the main papers and books.

“Neutrosophic Sets and Systems” has been created for publications on advanced studies in neutrosophy, neutrosophic set, neutrosophic logic, neutrosophic probability, neutrosophic statistics that started in 1995 and their applications in any field, such as the neutrosophic structures developed in algebra, geometry, topology, etc.

Abstract: Contributors to current issue (listed in papers' order): K Mondal, S. Pramanik, F. Smarandache, M. A. Malik, A. Hassan, S. Broumi, S. K. De, I. Beg, A. N. H. Zaied, H. M. Naguib, N. Shah, A. A. Salama, M. Eisa, H. E. Ghawalby, A. E. Fawzy, M. Sarkar, S. Dey, T. K. Roy, S. Karatas, C. Kuru, P. J. M. Vera, C. F. M. Delgado, M. P. Gónzalez, M. L. Vázquez, Tuhin Bera, and Nirmal Kumar Mahapatra. Papers in current issue (listed in papers' order): Multi-attribute Decision Making based on Rough Neutrosophic Variational Coefficient Similarity Measure; Regular Single Valued Neutrosophic Hypergraphs; Triangular Dense Fuzzy Neutrosophic Sets; Applications of Fuzzy and Neutrosophic Logic in Solving Multi-criteria Decision Making Problems; Irregular Neutrosophic Graphs; Neutrosophic Features for Image Retrieval; Truss Design Optimization using Neutrosophic Optimization Technique; Marketing skills as determinants that underpin the competitiveness of the rice industry in Yaguachi canton. Application of SVN numbers to the prioritization of strategies; Classical Logic and Neutrosophic Logic. Answers to K. Georgiev; Regular Bipolar Single Valued Neutrosophic Hypergraphs; Neutrosophic Topology; Neutrosophic crisp Sets via Neutrosophic crisp Topological Spaces; Rough Neutrosophic TOPSIS for Multi-Attribute Group Decision Making; Introduction to Neutrosophic Soft Groups. Keywords: neutrosophy, neutrosophic set, neutrosophic logic, neutrosophic probability, neutrosophic statistics, neutrosophic measure, neutrosophic applications.

This twelfth volume of Collected Papers includes 86 papers comprising 976 pages on Neutrosophics Theory and Applications, published between 2013-2021 in the international journal and book series “Neutrosophic Sets and Systems” by the author alone or in collaboration with the following 112 co-authors (alphabetically ordered) from 21 countries: Abdel Nasser H. Zaied, Muhammad Akram, Bobin Albert, S. A. Alblowi, S. Anitha, Guennoun Asmae, Assia Bakali, Ayman M. Manie, Abdul Sami Awan, Azeddine Elhassouny, Erick González-Caballero, D. Dafik, Mithun Datta, Arindam Dey, Mamouni Dhar, Christopher Dyer, Nur Ain Ebas, Mohamed Eisa, Ahmed K. Essa, Faruk Karaaslan, João Alcione Sganderla Figueiredo, Jorge Fernando Goyes García, N. Ramila Gandhi, Sudipta Gayen, Gustavo Alvarez Gómez, Sharon Dinarza Álvarez Gómez, Haitham A. El-Ghareeb, Hamiden Abd El-Wahed Khalifa, Masooma Raza Hashmi, Ibrahim M. Hezam, German Acurio Hidalgo, Le Hoang Son, R. Jahir Hussain, S. Satham Hussain, Ali Hussein Mahmood Al-Obaidi, Hays Hatem Imran, Nabeela Ishfaq, Saeid Jafari, R. Jansi, V. Jeyanthi, M. Jeyaraman, Sripati Jha, Jun Ye, W.B. Vasantha Kandasamy, Abdullah Kargın, J. Kavikumar, Kawther Fawzi Hamza Alhasan, Huda E. Khalid, Neha Andalleb Khalid, Mohsin Khalid, Madad Khan, D. Koley, Valeri Kroumov, Manoranjan Kumar Singh, Pavan Kumar, Prem Kumar Singh, Ranjan Kumar, Malayalan Lathamaheswari, A.N. Mangayarkkarasi, Carlos Rosero Martínez, Marvelio Alfaro Matos, Mai Mohamed, Nivetha Martin, Mohamed Abdel-Basset, Mohamed Talea, K. Mohana, Muhammad Irfan Ahamad, Rana Muhammad Zulqarnain, Muhammad Riaz, Muhammad Saeed, Muhammad Saqlain, Muhammad Shabir, Muhammad Zeeshan, Anjan Mukherjee, Mumtaz Ali, Deivanayagampillai Nagarajan, Iqra Nawaz, Munazza Naz, Roan Thi Ngan, Necati Olgun, Rodolfo González Ortega, P. Pandiammal, I. Pradeepa, R. Princy, Marcos David Oviedo Rodríguez, Jesús Estupiñán Ricardo, A. Rohini, Sabu Sebastian, Abhijit Saha, Mehmet Șahin, Said Broumi, Saima Anis, A.A. Salama, Ganeshsree Selvachandran, Seyed Ahmad Edalatpanah, Sajana Shaik, Soufiane Idbrahim, S. Sowndrarajan, Mohamed Talea, Ruipu Tan, Chalapathi Tekuri, Selçuk Topal, S. P. Tiwari, Vakkas Uluçay, Maikel Leyva Vázquez, Chinnadurai Veerappan, M. Venkatachalam, Luige Vlădăreanu, Ştefan Vlăduţescu, Young Bae Jun, Wadei F. Al-Omeri, Xiao Long Xin.

“Neutrosophic Sets and Systems” has been created for publications on advanced studies in neutrosophy, neutrosophic set, neutrosophic logic, neutrosophic probability, neutrosophic statistics that started in 1995 and their applications in any field, such as the neutrosophic structures developed in algebra, geometry, topology, etc.

In recent time graphical analytics of uncertainty and indeterminacy has become major concern for data analytics researchers. In this direction, the mathematical algebra of neutrosophic graph is extended to interval-valued neutrosophic graph. However, building the interval-valued neutrosophic graphs, its spectrum and energy computation is addressed as another issues by research community of neutrosophic environment. To resolve this issue the current paper proposed some related mathematical notations to compute the spectrum and energy of interval-valued neutrosophic graph using the MATAB.