Perhaps you should try some spelling variations:
cham truc » cau truc, pham thuc, nam truc
ban thanh » ban hanh, ban hang
nham thuc » nhan thuc, nam thuc, nham thu
so sach » so sanh, bo sach, co sach
vu nang » vuc nang, va nang, vu dang
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
sach vu » sach va, sach tu, sach uu
di cua » doi cua, de cua, do cua
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach vu nang ma hoi. hieu ve ((cham truc) or (nham thuc)) ban thanh ((di cua) OR (dai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach vu nang ma hoi. hieu ve ((cham truc) OR (nham thuc)) ban thanh ((di cua) OR (dai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach vu nang ma hoi. hieu ve ((cham truc) or (nham thuc)) ban thanh ((di cua) OR (dai cua)) te".
• Adding a wildcard symbol may retrieve word variants: so sach vu nang ma hoi. hieu ve ((cham truc) or (nham thuc)) ban thanh ((di cua) OR (dai cua)) te*.