http://kxaydung.duytan.edu.vn/Upload/Files/4ae43ada-b607-4331-8caa-f9f0402925a21999[1][1].TCVN_229-Chi_dan_Tinh_toan_Thanh_phan_dong_cua_Tai_trong_gio_theo_TCVN_2737-1995.pdf