Perhaps you should try some spelling variations:
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
ma hoi » mai hoi, xa hoi, ma hoa
va hai » van hai, va chai, va khai
hai xu » thai xu, hai vu, dai xu
va cau » van cau, va cac, va dau

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 ky nang ma hoi. hieu va hai xu ((van hanh) OR (ban hanh)) va cau thi~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ma hoi. hieu va hai xu ((van hanh) OR (ban hanh)) va cau thi".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. hieu va hai xu ((van hanh) OR (ban hanh)) va cau thi*.