Perhaps you should try some spelling variations:
hieu van » thien van, lieu va
dang xay » dang van, van xay
vu sach » vu bach, su sach, vu khach
tinh va » tich va, trinh van, trinh vat
xa tinh » va tinh, ha tinh, ca tinh
coc tuc » coc luc, hoc thuc, doc thuc
hieu va » lieu va, hieu qua
so viet » hoc viet
sach ky » sac ky, sach y, sach ty
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
va so » ma so, va su, va co

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky dang xay hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) coc tuc xa tinh va so viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky dang xay hoi. ((((hieu ve) OR (hieu van))) OR (hieu va)) coc tuc xa tinh va so viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky dang xay hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) coc tuc xa tinh va so viet".
• Adding a wildcard symbol may retrieve word variants: vu sach ky dang xay hoi. ((((hieu ve) OR (hieu van))) or (hieu va)) coc tuc xa tinh va so viet*.