Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thu sach » tu sach, thuat sach, thuoc sach
cham duc » pham duc, cham soc, pham duy
van hanh » ban hanh, van anh, van ban
va triet » va thiet, va trien, ve triet
hieu vu » hieu va, hieu ve, hieu su
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
vu cham » va cham, vu kham, tu cham
tai va » thai va, mai va, tri va

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 ((nang ma) or (nang x)) hoi. hieu vu cham duc ((van hanh) OR (van thanh)) tai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang ma) OR (nang x)) hoi. hieu vu cham duc ((van hanh) OR (van thanh)) tai va triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((nang ma) or (nang x)) hoi. hieu vu cham duc ((van hanh) OR (van thanh)) tai va triet*".