Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cham duc » pham duc, cham soc, pham duy
van hanh » van thanh, ban hanh, van anh
sach ty » sach tu, sach thu, xach tay
duc van » duc va, duc tan, duc manh
vi cua » vai cua
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ty) or (sach y)) nang x hoi. hieu van cham duc van hanh ((vi cua) OR (di cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach y)) nang x hoi. hieu van cham duc van hanh ((vi cua) OR (di cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) or (sach y)) nang x hoi. hieu van cham duc van hanh ((vi cua) OR (di cua)) triet".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) or (sach y)) nang x hoi. hieu van cham duc van hanh ((vi cua) OR (di cua)) triet*.