Perhaps you should try some spelling variations:
nang tai » tang tai, sang tai, nang cao
ve triet » va trien, su triet
hang tai » hang va, dung tai
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
cam luu » tam luu
hanh ki » hanh vi, hanh ky, hanh kien
luu van » cuu van, luan van, luu hanh
su viet » so viet
sach vu » sach va, sach tu, sach uu
hieu va » lieu va, hieu qua
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach vu ((nang tai) or (hang tai)) hoi. hieu va cam luu van hanh ki ((ve triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vu ((nang tai) OR (hang tai)) hoi. hieu va cam luu van hanh ki ((ve triet) OR (su viet)).
• Adding a wildcard symbol may retrieve word variants: tu sach vu ((nang tai) or (hang tai)) hoi. hieu va cam luu van hanh ki ((ve triet) or (su viet))*.