Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
cau treo » cau theo, cau tren, cau triet
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cau duc » cao duc, cau luc, chu duc
va hanh » van hanh, va thanh, va danh
vi cau » va cau, ve cau, di cau

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

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