Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
van tuan » van quan, van ban, anh tuan
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty dang » ty xang, ky dang, ty hang
dang xa » dang xay, lang xa, dang ha
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac

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 ty dang xa hoi. hieu va cac tuc ((van hanh) or (van tuan)) hoi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty dang xa hoi. hieu va cac tuc ((van hanh) OR (van tuan)) hoi va triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty dang xa hoi. hieu va cac tuc ((van hanh) or (van tuan)) hoi va triet*.