Perhaps you should try some spelling variations:
cham truc » nham thuc, pham thuc, nam truc
van hanh » van thanh, ban hanh, van anh
cac tieu » cach tieu, cac trieu, cac kieu
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hanh va » hang va, hanh vi

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky tang xa hoi. hieu qua ((cham truc) or (cau truc)) van hanh va cac tieu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky tang xa hoi. hieu qua ((cham truc) OR (cau truc)) van hanh va cac tieu.
• Adding a wildcard symbol may retrieve word variants: vu sach ky tang xa hoi. hieu qua ((cham truc) or (cau truc)) van hanh va cac tieu*.