Perhaps you should try some spelling variations:
cach thuc » anh thuc, cac thu
cua viet » ca viet, hoa viet, cua vat
thanh vi » hanh vi, thanh va, thanh ve
thuc gia » thuc giai, thue gia, thuc dia
cuu tre » cua tre, cau tren, cau treo
va cach » va cac
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y ((nang xa) OR (nang ma)) hoi. hieu va cach thuc gia thanh vi ((cuu tre) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((nang xa) OR (nang ma)) hoi. hieu va cach thuc gia thanh vi ((cuu tre) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y ((nang xa) OR (nang ma)) hoi. hieu va cach thuc gia thanh vi ((cuu tre) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: so sach y ((nang xa) OR (nang ma)) hoi. hieu va cach thuc gia thanh vi ((cuu tre) or (cua viet))*.