Perhaps you should try some spelling variations:
va thieu » va thiet, va hieu, va tieu
van hanh » van thanh, ban hanh, van anh
van danh » van doanh, van anh, van manh
sach ty » sach y, sach tu, sach thu
su sach » so sach, vu sach
ve chao » ve chat, ve cham, ve chang
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
ve cho » ve co, ve che, de cho
ma hoi » mai hoi, xa hoi, ma hoa
va va » va van, va vua, va vai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty nang ma hoi. hieu ((ve chao) or (ve cho)) xu ((van danh) OR (van hanh)) va va thieu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ma hoi. hieu ((ve chao) OR (ve cho)) xu ((van danh) OR (van hanh)) va va thieu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang ma hoi. hieu ((ve chao) or (ve cho)) xu ((van danh) OR (van hanh)) va va thieu".
• Adding a wildcard symbol may retrieve word variants: su sach ty nang ma hoi. hieu ((ve chao) or (ve cho)) xu ((van danh) OR (van hanh)) va va thieu*.