Perhaps you should try some spelling variations:
hoc viet » hoc hien
va thanh » gia thanh, ban thanh, va tinh
nam thuc » nam thuoc, am thuc, nam thu
va hanh » van hanh, va danh, ban hanh
so sanh » do sanh
hieu ve » hieu va, hieu van
ly vang » ly van, ly quang
ly hang » ly quang
ma hoi » mai hoi, xa hoi, ma hoa
vi hoc » li hoc, va hoc
ve nam » he nam, va nam, le nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sanh ((ly hang) or (ly vang)) ma hoi. hieu ve nam thuc ((va hanh) or (va thanh)) vi hoc viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sanh ((ly hang) OR (ly vang)) ma hoi. hieu ve nam thuc ((va hanh) OR (va thanh)) vi hoc viet.
• Adding a wildcard symbol may retrieve word variants: so sanh ((ly hang) or (ly vang)) ma hoi. hieu ve nam thuc ((va hanh) or (va thanh)) vi hoc viet*.