Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
cham luc » cham soc, nhan luc, cham cuu
van hang » van khang, van hoang, van thang
va nang » van nang, da nang, cam nang
va hang » va lang, va hanh, ban hang
sach ky » sac ky, sach y, sach ty
te sach » toc sach
vu cham » va cham, vu kham, tu cham
hieu vu » hieu va, hieu ve, hieu su
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
ma hoi » mai hoi, xa hoi, ma hoa
dau va » dau ve, lau va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky tang ma hoi. hieu vu cham luc ((((va hang) OR (va nang))) or (van hang)) dau va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky tang ma hoi. hieu vu cham luc ((((va hang) OR (va nang))) OR (van hang)) dau va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky tang ma hoi. hieu vu cham luc ((((va hang) OR (va nang))) or (van hang)) dau va triet".
• Adding a wildcard symbol may retrieve word variants: te sach ky tang ma hoi. hieu vu cham luc ((((va hang) OR (va nang))) or (van hang)) dau va triet*.