Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thu sach » thuat sach, thuoc sach, thu hoach
nang dai » nang dau, nang tai, lang dai
cao vuc » cao duc, cao suc, cao vu
vuc van » duc van, luc van, thuc van
tu sach » su sach, te sach, tu cach
hieu va » lieu va, hieu qua
dai hoi » dai hoc, dai hai, dai moi
y nang » ky nang, ly nang, v nang
vi cua » vai cua
di cua » dai cua, doi cua, de cua
va cao » va cac, va co, va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) y nang dai hoi. hieu va cao vuc van thanh ((vi cua) OR (di cua)) quoc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) y nang dai hoi. hieu va cao vuc van thanh ((vi cua) OR (di cua)) quoc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) y nang dai hoi. hieu va cao vuc van thanh ((vi cua) OR (di cua)) quoc".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) y nang dai hoi. hieu va cao vuc van thanh ((vi cua) OR (di cua)) quoc*.