Free vibration characteristic analysis of functionally graded shells with porosity and neutral surface effects Authors Pham ToanThang, Dieu T.T.Do, Tan-TienNguyen, Jae hong Lee, T.Nguyen-Thoi Publication year 2022 Index (WoS/Scopus) WoS Publisher Elsevier Journal Ocean Engineering Link https://www.sciencedirect.com/science/article/abs/pii/S002980182200765X?via%3Di…