Perhaps you should try some spelling variations:
hoc thuc » hoc huu
te sach » toc sach
sach tu » sach thu, cach tu, sach ty
tu nong » tu dong, tu cong, tu tong
nong xa » song xa, dong xa, nong va
hieu va » lieu va, hieu qua
co thuc » do thuc, co thua, mo thuc
va hanh » van hanh, va thanh, va danh
vai cua » hai cua, lai cua, bai cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach tu nong xa hoi. hieu va ((co thuc) or (hoc thuc)) va hanh ((vai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu nong xa hoi. hieu va ((co thuc) OR (hoc thuc)) va hanh ((vai cua) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: te sach tu nong xa hoi. hieu va ((co thuc) or (hoc thuc)) va hanh ((vai cua) or (dai cua)) tre*.