Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
va nang » van nang, da nang, cam nang
va hang » van hang, va lang, va hanh
te sach » toc sach
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
so sanh » do sanh
cuu tre » cua tre, cau tren, cau treo
ve cam » ve cham, ve cac, va cam
di cuu » di cau, di cua, dinh cuu

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) or (so sanh)) ky nang xa hoi. hieu ve cam thuc ((va hang) OR (va nang)) di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (so sanh)) ky nang xa hoi. hieu ve cam thuc ((va hang) OR (va nang)) di cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (so sanh)) ky nang xa hoi. hieu ve cam thuc ((va hang) OR (va nang)) di cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (so sanh)) ky nang xa hoi. hieu ve cam thuc ((va hang) OR (va nang)) di cuu tre*.