Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu cao » chieu cao, hieu cac, hieu ca
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cao cau » cao cap, co cau, tao cau
va danh » va dinh, va hanh, dia danh
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau

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

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