Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
nam thuc » nam thuoc, am thuc, nam thu
toc sac » toc sach, toc san, hoc sach
va hanh » va thanh, va danh, ban hanh
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
tai cua » thai cua, tai cuc, tri cua
cua te » cua tu
sac ky » cac ky, sai ky
nam tu » nam thu

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

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