Perhaps you should try some spelling variations:
hang truc » khung truc
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
dai truc » dai thuc, doan truc, dai trung
vu sach » vu bach, su sach, vu khach
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
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: vu sach ky lang xa hoi. hieu va ((hang 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: vu sach ky lang xa hoi. hieu va ((hang truc) OR (dai truc)) ((ban hanh) OR (van hanh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: vu sach ky lang xa hoi. hieu va ((hang truc) or (dai truc)) ((ban hanh) or (van hanh)) vi cua tre*.