Perhaps you should try some spelling variations:
hoc viet » hoc hien
van hanh » van thanh, ban hanh, van anh
bach thu » bach nhu, sach thu, bich thuy
tuc van » thuc van, truc van, tuc va
bach tu » cach tu, bac tu, sach tu
may hoi » may thoi, tay hoi, mai hoi
va cam » va cham, va cac, va cao
vi hoc » li hoc, va hoc
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: vu ((bach tu) OR (bach thu)) mang may hoi. hieu ((ve cac) or (va cam)) tuc van hanh vi hoc viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((bach tu) OR (bach thu)) mang may hoi. hieu ((ve cac) OR (va cam)) tuc van hanh vi hoc viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu ((bach tu) OR (bach thu)) mang may hoi. hieu ((ve cac) or (va cam)) tuc van hanh vi hoc viet*".