Perhaps you should try some spelling variations:
so nganh » so ngan, hoc nganh, moi nganh
nganh ky » nganh y, nganh xay, hanh ky
hanh hai » thanh hai, nhanh hai, hanh tai
hang hai » hoang hai, hang tai, thanh hai
ky hang » ky nang, ly hang, ky dang
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
cua tre » cua te, cuu tre, cua triet
va hoi » xa hoi, va hoc, va hoa
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: so nganh ky hang va hoi. hieu ve cac duc va ((hanh hai) or (hang hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so nganh ky hang va hoi. hieu ve cac duc va ((hanh hai) OR (hang hai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: so nganh ky hang va hoi. hieu ve cac duc va ((hanh hai) or (hang hai)) cua tre*.