Perhaps you should try some spelling variations:
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
lang ha » long ha
hieu va » lieu va, hieu qua
cam loc » cam lo
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
loc va » hoc va, luc va
vi cua » vai cua, di cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky ((lang ha) OR (van xay)) hoi. hieu va cam loc va hanh vi cua tre~.
• Adding a wildcard symbol may retrieve word variants: vu sach ky ((lang ha) or (van xay)) hoi. hieu va cam loc va hanh vi cua tre*.