Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cham hoc » cham soc, chat hoc, cho hoc
cham hoi » cham voi, cham h'roi, pham hoai
cua viet » ca viet, hoa viet, cua vat
te sach » toc sach
vu sach » vu bach, su sach, vu khach
lang xa » lang ha, dang xay, lang van
va hanh » van hanh, va thanh, va danh
y lang » o lang, _ lang, tay lang
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 lang xa hoi. hieu van ((cham hoc) OR (cham hoi)) va hanh vi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (vu sach)) y lang xa hoi. hieu van ((cham hoc) OR (cham hoi)) va hanh vi cua viet~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (vu sach)) y lang xa hoi. hieu van ((cham hoc) OR (cham hoi)) va hanh vi cua viet*.