Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
hieu san » hieu van, hieu sau, chieu sang
van hanh » van thanh, ban hanh, van anh
tu sach » su sach, te sach, tu cach
nang xa » nang x, lang xa, nang ma
duc van » duc va, duc tan, duc manh
vai cua » dai cua, hai cua, lai cua
di cua » dai cua, doi cua, de cua
pham » phan

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) OR (thu sach)) ky nang xa hoi. hieu san pham duc van hanh ((vai cua) or (di cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang xa hoi. hieu san pham duc van hanh ((vai cua) OR (di cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky nang xa hoi. hieu san pham duc van hanh ((vai cua) or (di cua)) triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky nang xa hoi. hieu san pham duc van hanh ((vai cua) or (di cua)) triet*.