Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
do thuc » hoc thuc, dan thuc
lai cua » dai cua, hai cua, thai cua
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
sach tu » cach tu, sach ty, sach uu
va do » va dao, va doc, va co
x hoi » xa hoi, o hoi, x ho

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) or (sach thu)) nang x hoi. hieu va do thuc va danh ((lai cua) OR (lai chau)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach tu) OR (sach thu)) nang x hoi. hieu va do thuc va danh ((lai cua) OR (lai chau)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach tu) or (sach thu)) nang x hoi. hieu va do thuc va danh ((lai cua) OR (lai chau)) tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach tu) or (sach thu)) nang x hoi. hieu va do thuc va danh ((lai cua) OR (lai chau)) tre*.