Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
ky lang » ky nang, ky dang, tay lang
ky tang » ky nang, ky dang, kho tang
hieu va » lieu va, hieu qua
va tuan » van tuan, va quan, va toan
va hanh » va thanh, va danh, ban hanh
luu tre » luu tru, cuu tre, luy tre
te sac » te sach, te cac, te san
vi luu » vi lua

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

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