Perhaps you should try some spelling variations:
nang dau » hang dau, xang dau, nang du
hang hai » hoang hai, hang tai, thanh hai
su sach » so sach, vu sach
dau hai » dai hai, dau ha, cau hai
hieu ve » hieu va, hieu van
cua tre » cuu tre, cua triet, dua tren
sach ky » sac ky, sach y, sach ty
cua te » cua tu
tuc va » thuc va, truc va, tuc xa
luc va » duc va, loc va
ve cac » va cac, vien cac

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