Perhaps you should try some spelling variations:
thanh son » thanh san, thanh cong, thanh toan
thanh soc » nhanh soc, thanh hoc, thanh ngoc
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
te sach » toc sach
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
luu tre » luu tru, cuu tre, luy tre
sach ky » sac ky, sach y, sach ty
xay hoi » xa hoi, tay hoi, cay phoi
ky dang » ky nang, ky danh
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 dang xay hoi. hieu van ((thanh soc) OR (thanh son)) ((va danh) or (va hanh)) vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky dang xay hoi. hieu van ((thanh soc) OR (thanh son)) ((va danh) OR (va hanh)) vi luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky dang xay hoi. hieu van ((thanh soc) OR (thanh son)) ((va danh) or (va hanh)) vi luu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky dang xay hoi. hieu van ((thanh soc) OR (thanh son)) ((va danh) or (va hanh)) vi luu tre*.