Perhaps you should try some spelling variations:
hai truc » hai trac, hang truc, thai thuc
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
dai truc » dai thuc, doan truc, dai trung
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
vi cua » vai cua, di cua

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 truc) or (dai truc)) ((ban hanh) or (van hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ma hoi. hieu va ((hai truc) OR (dai truc)) ((ban hanh) OR (van hanh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. hieu va ((hai truc) or (dai truc)) ((ban hanh) or (van hanh)) vi cua tre*.