Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
ve triet » va trien, su triet
sach ty » sach y, sach tu, sach thu
hieu ve » hieu van
sach ky » sac ky, sach y, sach kem
hieu va » lieu va, hieu qua
hanh va » hang va, hanh vi
bo van » vo van, so van, do van
x hoi » xa hoi, o hoi, x ho
va ve » va de, va le, va vi

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (sach ty)) nang x hoi. ((hieu ve) OR (hieu va)) bac bo van hanh va ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach ty)) nang x hoi. ((hieu ve) OR (hieu va)) bac bo van hanh va ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) or (sach ty)) nang x hoi. ((hieu ve) OR (hieu va)) bac bo van hanh va ve triet".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sach ty)) nang x hoi. ((hieu ve) OR (hieu va)) bac bo van hanh va ve triet*.