Perhaps you should try some spelling variations:
sang tai » hang tai, sang tao, sang than
tang tai » hang tai, dung tai, sang tao
hieu va » lieu va, hieu qua
danh vi » hanh vi, dinh vi, danh di
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
xuc va » tuc va, luc va, xac va
vi cua » vai cua, di cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky ((sang tai) OR (tang tai)) hai. hieu va cac ((xuc va) or (duc va)) danh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky ((sang tai) OR (tang tai)) hai. hieu va cac ((xuc va) OR (duc va)) danh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky ((sang tai) OR (tang tai)) hai. hieu va cac ((xuc va) or (duc va)) danh vi cua te".
• Adding a wildcard symbol may retrieve word variants: vu sach ky ((sang tai) OR (tang tai)) hai. hieu va cac ((xuc va) or (duc va)) danh vi cua te*.