Perhaps you should try some spelling variations:
te sach » toc sach
cua tre » cua te, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
cac luc » cau luc, coc luc, cac nuoc
hieu va » lieu va, hieu qua
lang ha » long ha
ky lang » ky nang, ky dang, ky tang
su sach » so sach, vu sach
cuu tre » cau tren, cau treo
ha hoi » hoa hoi, ha noi, xa hoi
luc va » duc va, tuc va, loc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (su sach)) ky lang ha hoi. hieu va cac luc va hanh vi ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (su sach)) ky lang ha hoi. hieu va cac luc va hanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (su sach)) ky lang ha hoi. hieu va cac luc va hanh vi ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (su sach)) ky lang ha hoi. hieu va cac luc va hanh vi ((cua tre) OR (cuu tre))*.