Perhaps you should try some spelling variations:
hoc quoc » hoc nuoc, hoc duoc, hoc thuoc
ky mang » ky nang, ke mang, ky dang
may hoi » may thoi, tay hoi, mai hoi
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
va tinh » may tinh
cua tre » cua te, cuu tre, cua triet
vu sac » vu sach, vu san, va sac
sac ky » cac ky, sai ky
va hoc » van hoc
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 sac ky mang may hoi. hieu va hoc quoc ((va danh) OR (va tinh)) vi cua tre~.
• Adding a wildcard symbol may retrieve word variants: vu sac ky mang may hoi. hieu va hoc quoc ((va danh) or (va tinh)) vi cua tre*.