Perhaps you should try some spelling variations:
van hoang » van hoan, quan hoang, tran hoang
cau treo » cau theo, cau tren, cau triet
nam thuc » nam thuoc, am thuc, nam thu
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren
tu sach » thu sach, su sach, te sach
qua nam » quan nam, cua nam, quang nam
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
va hang » van hang, va nang, va lang

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 ky dang xa hoi. hieu qua nam thuc ((va hang) or (van hoang)) di ((cuu tre) OR (cau treo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang xa hoi. hieu qua nam thuc ((va hang) OR (van hoang)) di ((cuu tre) OR (cau treo))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky dang xa hoi. hieu qua nam thuc ((va hang) or (van hoang)) di ((cuu tre) OR (cau treo))*".