Perhaps you should try some spelling variations:
hieu quan » lieu quan, thien quan, lien quan
danh vai » danh sai, danh va, doanh van
tu mach » tu cach, tu manh, tu hach
so lang » o lang, so dang, hoa lang
lang xa » lang ha, dang xay, lang van
cau duc » cao duc, cau luc, chu duc
va danh » va dinh, va dan, va hanh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu mach so lang xa hoi. ((hieu quan) or (hieu qua)) cau duc va danh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu mach so lang xa hoi. ((hieu quan) OR (hieu qua)) cau duc va danh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu mach so lang xa hoi. ((hieu quan) or (hieu qua)) cau duc va danh vai cua tre*.