Perhaps you should try some spelling variations:
thien van » thi van
tai khoi » tai khoa, mai khoi, tao khoi
van tuan » van quan, van ban, anh tuan
tuan hoc » toan hoc, luan hoc, than hoc
te sach » toc sach
vu sach » vu bach, su sach, vu khach
tai hoi » dai hoi, tai hai, tai hoe
va hanh » van hanh, va thanh, va danh
y hang » ly hang, ty hang, yu hang
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: ((te sach) OR (vu sach)) y hang ((tai hoi) OR (tai khoi)). thien van tuan hoc va hanh vi cua vat~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (vu sach)) y hang ((tai hoi) OR (tai khoi)). thien van tuan hoc va hanh vi cua vat~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (vu sach)) y hang ((tai hoi) OR (tai khoi)). thien van tuan hoc va hanh vi cua vat*.