Perhaps you should try some spelling variations:
sao trieu » tan trieu, cac trieu, mao triet
cau trieu » cac trieu, cau triet, chua trieu
nam thuc » nam thuoc, am thuc, nam thu
vanh tai » van tai, hanh tai, anh tai
sach ty » sach tu, sach thu, xach tay
nang xa » nang x, lang xa, nang ma
qua nam » quan nam, cua nam, quang nam
thuc va » thuc vat, thuc dan, thuc day
va vanh » va van, va danh, va hanh

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 ty) or (sach y)) nang xa hoi. hieu qua nam thuc va vanh tai ((sao trieu) OR (cau trieu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ty) OR (sach y)) nang xa hoi. hieu qua nam thuc va vanh tai ((sao trieu) OR (cau trieu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ty) or (sach y)) nang xa hoi. hieu qua nam thuc va vanh tai ((sao trieu) OR (cau trieu))".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ty) or (sach y)) nang xa hoi. hieu qua nam thuc va vanh tai ((sao trieu) OR (cau trieu))*.