Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
cac thuc » cach thuc, cac thu, can thuc
thuc va » thuc vat, thuc dan, thuc day
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau
dan de » dan den, dang de, van de
de cua » le cua, te cua, dieu cua

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

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