Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu ve » hieu va, hieu van
tu sac » tu sach, tu san, tu bac
ve nam » he nam, va nam, le nam
vai va » mai va, dai va, hai va
vi va » vi van, vu va, bi va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sac) OR (tu cac)) ky dang xa hoi. hieu ve nam thuc van hanh ((vi va) or (vai va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu cac)) ky dang xa hoi. hieu ve nam thuc van hanh ((vi va) OR (vai va)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sac) OR (tu cac)) ky dang xa hoi. hieu ve nam thuc van hanh ((vi va) or (vai va)) triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sac) OR (tu cac)) ky dang xa hoi. hieu ve nam thuc van hanh ((vi va) or (vai va)) triet*.