Perhaps you should try some spelling variations:
duoc tren » nuoc tren, thuoc tren, dung tren
dinh tai » dinh toai, dinh tri, dinh thi
nam thuc » nam thuoc, am thuc, nam thu
nang xa » nang x, lang xa, nang ma
te sach » toc sach
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va dinh » van dinh, va kinh, va tinh
duc tre » duc tien
tu sach » thu sach, su sach, tu cach
y nang » ky nang, ly nang, v nang
ve nam » he nam, va nam, le nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (te sach)) y nang xa hoi. hieu ve nam thuc va dinh tai ((duc tre) OR (duoc tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) y nang xa hoi. hieu ve nam thuc va dinh tai ((duc tre) OR (duoc tren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) y nang xa hoi. hieu ve nam thuc va dinh tai ((duc tre) OR (duoc tren))*".