Jantima, N. and Chaichana, N. (2026) “ The Development of Scientific Skills and Learning Achievement on Rocks and Fossils of Grade 6 Students at Phanpasoksawad School Using GPAS 5 Steps Learning Approach”, Education journal Faculty of Education, Nakhon Sawan Rajabhat University . Nakhon Sawan,Thailand, 9(2), pp. 30–45. doi: 10.2774.EDU2026.2.285183.