Perhaps you should try some spelling variations:
tuan doc » than doc, quan doc, tuan do
hieu van » thien van, lieu va, hieu ve
te sach » toc sach
dinh cu » dinh cuu, dinh chuc, dinh chau
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
dang ha » dong ha, dung ha, lang ha
ky dang » ky nang, ky danh
ha hoi » hoa hoi, ha noi, xa hoi
doc va » duoc va, hoc va, duc va
vi cuu » vi luu, vinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky dang ha hoi. ((hieu van) OR (hieu va)) tuan doc va hanh ((vi cuu) or (dinh cu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky dang ha hoi. ((hieu van) OR (hieu va)) tuan doc va hanh ((vi cuu) OR (dinh cu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky dang ha hoi. ((hieu van) OR (hieu va)) tuan doc va hanh ((vi cuu) or (dinh cu)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky dang ha hoi. ((hieu van) OR (hieu va)) tuan doc va hanh ((vi cuu) or (dinh cu)) tre*.