Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
thanh va » thanh van, hanh va, thanh ha
cua viet » ca viet, hoa viet, cua vat
sach ky » sac ky, sach ty, sach kem
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
truc va » thuc va, thuc vat, trung va
cua tre » cua te, cuu tre, cua triet
ve cau » ke cau, va cau, ve 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) OR (sach y)) lang xa hoi. hieu ve cau truc va thanh va ((cua tre) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach y)) lang xa hoi. hieu ve cau truc va thanh va ((cua tre) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sach y)) lang xa hoi. hieu ve cau truc va thanh va ((cua tre) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sach y)) lang xa hoi. hieu ve cau truc va thanh va ((cua tre) or (cua viet))*.