Perhaps you should try some spelling variations:
su sach » so sach, vu sach
ky sang » ky nang, ky dang, ky tang
lap hai » lap tai, lap hoat, lanh hai
dinh vi » dinh ve, dinh viet, dinh tri
lap lai » lap tai, lay lai, lam lai
sach ky » sac ky, sach y, sach ty
va dinh » van dinh, va kinh, va tinh
vi cua » vai cua, di cua
luc va » duc va, tuc va, loc va
ve cam » ve cham, va cam, ve cai
ve cac » va cac, vien cac
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: su sach ky sang ((lap hai) or (lap lai)). hieu ((ve cam) OR (ve cac)) luc va dinh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky sang ((lap hai) OR (lap lai)). hieu ((ve cam) OR (ve cac)) luc va dinh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky sang ((lap hai) or (lap lai)). hieu ((ve cam) OR (ve cac)) luc va dinh vi cua te".
• Adding a wildcard symbol may retrieve word variants: su sach ky sang ((lap hai) or (lap lai)). hieu ((ve cam) OR (ve cac)) luc va dinh vi cua te*.