Perhaps you should try some spelling variations:
lang ha » long ha
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
hieu va » lieu va, hieu qua
vu sach » vu bach, vu khach
ky lang » ky nang, ky dang, ky tang
su sach » so sach
cua tre » cua te, cuu tre, cua triet
ha hoi » hoa hoi, ha noi, xa hoi
cac tu » cac thu, cach tu, cac du
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) or (su sach)) ky lang ha hoi. hieu va cac tu ((va danh) OR (va hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (su sach)) ky lang ha hoi. hieu va cac tu ((va danh) OR (va hanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (su sach)) ky lang ha hoi. hieu va cac tu ((va danh) OR (va hanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (su sach)) ky lang ha hoi. hieu va cac tu ((va danh) OR (va hanh)) vi cua tre*.