Perhaps you should try some spelling variations:
dieu cua » dieu tra
dang xay » dang van, van xay
van hanh » van thanh, ban hanh, van anh
duc van » duc va, duc tan, duc manh
ky dang » ky nang, ky danh
xay hoi » xa hoi, tay hoi, cay phoi
de cua » le cua, te cua
tu san » thu san, tu ban, vu san
ca duc » cao duc, cua duc, ca dua
tu can » tu ban, tu cac, thu canh
qua ca » qua cac, qua cua, qua cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu san) OR (tu can)) ky dang xay hoi. hieu qua ca duc van hanh ((de cua) or (dieu cua)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu san) OR (tu can)) ky dang xay hoi. hieu qua ca duc van hanh ((de cua) OR (dieu cua)) viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu san) OR (tu can)) ky dang xay hoi. hieu qua ca duc van hanh ((de cua) or (dieu cua)) viet*".