On the thermal buckling analysis of functionally graded plates with internal defects using extended isogeometric analysis /Tiantang Yu a, ⇑ , Tinh Quoc Bui b, ⇑ , Shuohui Yin a , Duc Hong Doan c , C.T. Wu d , Thom Van Do e , Satoyuki Tanaka f - Yu,Tiantang