Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
hanh mai » hanh ma, hanh mau, hanh may
van hanh » van thanh, ban hanh, van anh
cham duc » pham duc, cham soc, pham duy
va triet » va thiet, va trien, ve triet
nang ma » tang ma, sang ma, nang cao
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
duc van » duc va, duc tan, duc manh
tu sach » su sach, te sach, tu cach

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