Perhaps you should try some spelling variations:
cach thuc » anh thuc, cac thu
hieu van » hieu va, thien van, lieu va
van cach » va cach, van canh, vat cach
danh di » danh du, xanh di, danh dien
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
so sach » so sanh, bo sach, co sach
nang ma » tang ma, sang ma, nang cao
lang xa » lang ha, dang xay, lang van
nang xa » nang x, mang xa, ang xa
cuu tre » cua tre, cau tren, cau treo
di cuu » di cau, di cua, dinh cuu

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 (lang xa))) or (nang ma)) hoi. hieu van cach thuc va danh di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((((nang xa) OR (lang xa))) OR (nang ma)) hoi. hieu van cach thuc va danh di cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y ((((nang xa) OR (lang xa))) or (nang ma)) hoi. hieu van cach thuc va danh di cuu tre".
• Adding a wildcard symbol may retrieve word variants: so sach y ((((nang xa) OR (lang xa))) or (nang ma)) hoi. hieu van cach thuc va danh di cuu tre*.