Perhaps you should try some spelling variations:
su sach » so sach, vu sach
ky sang » ky nang, ky dang, duy sang
ky tang » ky nang, ky dang, kho tang
lap hai » lap tai, lap lai, lap hoat
hieu ve » hieu va, hieu van
cac luc » cau luc, coc luc, cac nuoc
dan vi » doan vi, don vi, dan va
ve cac » va cac, vien cac
va dan » ca dan, va dao, va dau
luc va » duc va, tuc va, loc va
cua tu » cua tuc, cua su, cua cu

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) or (ky tang)) lap hai. hieu ve cac luc va dan vi ((cua te) OR (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky sang) OR (ky tang)) lap hai. hieu ve cac luc va dan vi ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ky sang) or (ky tang)) lap hai. hieu ve cac luc va dan vi ((cua te) OR (cua tu))".
• Adding a wildcard symbol may retrieve word variants: su sach ((ky sang) or (ky tang)) lap hai. hieu ve cac luc va dan vi ((cua te) OR (cua tu))*.