Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
tham hoc » thai hoc, tham hoa, than hoc
te sach » toc sach
ky lang » ky dang, ky tang, tay lang
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
luu tre » luu tru, cuu tre, luy tre
vi luu » vi lua

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 lang) OR (ky nang)) xa hoi. ((hieu van) or (hieu va)) tham hoc va hanh vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ky lang) OR (ky nang)) xa hoi. ((hieu van) OR (hieu va)) tham hoc va hanh vi luu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ky lang) OR (ky nang)) xa hoi. ((hieu van) or (hieu va)) tham hoc va hanh vi luu tre*".