VNU Journal of Science Mathematics – Physics, Vol 37, No 1 (2021) 60 67 60 Original Article A Note on Invariant Basis Number and Types for Strongly Graded Rings Nguyen Quang Loc* Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi, Vietnam Received 11 April 2020 Revised 03 August 2020; Accepted 15 September 2020 Abstract Given any pair of positive integers (n, k) and any nontrivial finite group G, we show that there exists a ring R of type (n, k) such that R is strongly grad[.]