Perhaps you should try some spelling variations:
trinh thiet » trinh viet, trinh thi
thiet qua » thien quan, hieu qua, thien quy
qua tinh » qua trinh, quan tinh, qua kinh
tinh cua » trinh cua, sinh cua, tinh chat
viet nha » viet nhat, viet ha, viec nha
hien han » hien hanh, hien huan, dien han
nha hoc » nha thuoc, khoa hoc, nha nuoc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: giao trinh thiet qua tinh cua nguoi viet nha hoc hien han~.
• Adding a wildcard symbol may retrieve word variants: giao trinh thiet qua tinh cua nguoi viet nha hoc hien han*.