Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
nang tai » hang tai, tang tai, sang tai
than hoc » toan hoc, thai hoc, than doc
tuan hoc » toan hoc, luan hoc, quang hoc
tai hoi » tai khoi, dai hoi, tai hai
thi van » thi lan, thi hanh, thi nang
vu sach » vu bach, su sach, vu khach
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
te sach » toc sach
y nang » ky nang, ly nang, v nang
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 nang tai hoi. thi van ((tuan hoc) OR (than hoc)) va danh vi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (vu sach)) y nang tai hoi. thi van ((tuan hoc) OR (than hoc)) va danh vi cua viet~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (vu sach)) y nang tai hoi. thi van ((tuan hoc) OR (than hoc)) va danh vi cua viet*.