International Journal of Neutrosophic Science IJNS 2690-6805 2692-6148 10.54216/IJNS https://www.americaspg.com/journals/show/2899 2020 2020 Department of Applied Science, Ajloun College, Al Balqa Applied University, Ajloun 26816. Jordan. Jadara University Research Center, Jadara University, Jordan. Tariq Tariq Mathematics Education Program, Faculty of Education and Arts, Sohar University, Sohar 3111, Oman. Jadara University Research Center, Jadara University, Jordan. Ala Amourah College of Applied and Health Sciences, A’Sharqiyah University, Post Box No. 42, Post Code No. 400 Ibra, Sultanate of Oman. Jamal Salah Department of Mathematics, The University of Jordan, Amman 11942, Jordan. School of Engineering, Math & Technology, Navajo Technical University, Crownpoint, NM 87313, USA. Jadara University Research Center, Jadara University, Jordan. Feras Yousef The aim of this article is to establish two new and qualitative subfamilies F(ε, κ, ℵ) and G(ε, κ, ℵ) of biunivalent functions. For functions in these subfamilies, we determine the first two Maclaurin coefficient estimations |C2| and |C3|, and address the Fekete–Szeg¨o problem. Additionally, we mention some corollaries related to the main results.   2024 2024 315 323 10.54216/IJNS.240422 https://www.americaspg.com/articleinfo/21/show/2899