Perhaps you should try some spelling variations:
hieu san » hieu van, hieu sau, chieu sang
pham duy » pham duc
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
duy van » duy vat, dung van
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: tu sach ky nang x hoi. hieu san pham duy van hanh ((vi cua) or (di cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu san pham duy van hanh ((vi cua) OR (di cua)) triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu san pham duy van hanh ((vi cua) or (di cua)) triet*.