Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
va triet » va thiet, va trien, ve triet
thu sach » thuat sach, thuoc sach, thu hoach
van hanh » ban hanh, van anh, van ban
cac tuc » cac toc, cac tu, cac tac
tu sach » su sach, te sach, tu cach
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
hieu va » lieu va, hieu qua
vai va » mai va, dai va, hai va

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)) ky dang xa hoi. hieu va cac tuc ((van hanh) or (van thanh)) vai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky dang xa hoi. hieu va cac tuc ((van hanh) OR (van thanh)) vai va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky dang xa hoi. hieu va cac tuc ((van hanh) or (van thanh)) vai va triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky dang xa hoi. hieu va cac tuc ((van hanh) or (van thanh)) vai va triet*.