Perhaps you should try some spelling variations:
dang van » hoang van
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, thien van, lieu va
xuc van » duc van, luc van, vuc van
doi cua » dai cua, hoi cua
so sach » so sanh, bo sach, co sach
dau xuc » dau xac, dau xua, dau nuoc
sach ky » sac ky, sach y, sach ty
van dau » van dao, phan dau
di cua » dai cua, de cua, do cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky ((dang van) OR (hang va)) hoi. hieu van dau xuc van hanh ((di cua) or (doi cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((dang van) OR (hang va)) hoi. hieu van dau xuc van hanh ((di cua) OR (doi cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky ((dang van) OR (hang va)) hoi. hieu van dau xuc van hanh ((di cua) or (doi cua)) triet".
• Adding a wildcard symbol may retrieve word variants: so sach ky ((dang van) OR (hang va)) hoi. hieu van dau xuc van hanh ((di cua) or (doi cua)) triet*.