Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, thien van, lieu va
dau xuc » dau xac, dau xua, dau nuoc
doi cua » dai cua, hoi cua
xuc van » duc van, luc van, vuc van
so sach » so sanh, bo sach, hoc sach
ky hang » ky nang, ly hang, ky dang
co sach » bo sach, cuon sach, hoc sach
van dau » van dao, phan dau
va hoi » xa hoi, va hoc, va hoa
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) OR (co sach)) ky 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) OR (co sach)) ky 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) OR (co sach)) ky 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) OR (co sach)) ky hang va hoi. hieu van dau xuc van hanh ((di cua) or (doi cua)) triet*.