Perhaps you should try some spelling variations:
chau viet » chu viet, khau viet, cham viet
hanh lai » hanh lam, hanh tai, thanh lap
thuc dan » thuc hanh, hoc dan, thuc vat
van nham » van nam, van nhan, van tham
hieu van » hieu va, thien van, lieu va
thu bang » thu hang, chu bang, thu trang
thu ban » thu hang
thuc va » thuc vat, thuc day
vu sach » vu bach, su sach, vu khach
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ((thu bang) or (thu ban)) x hoi. hieu van nham ((thuc va) OR (thuc dan)) hanh lai chau viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ((thu bang) OR (thu ban)) x hoi. hieu van nham ((thuc va) OR (thuc dan)) hanh lai chau viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ((thu bang) or (thu ban)) x hoi. hieu van nham ((thuc va) OR (thuc dan)) hanh lai chau viet".
• Adding a wildcard symbol may retrieve word variants: vu sach ((thu bang) or (thu ban)) x hoi. hieu van nham ((thuc va) OR (thuc dan)) hanh lai chau viet*.