Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thien van » thi van
thanh vai » thanh hai, thanh van, thanh tai
hieu van » hieu va, lieu va, hieu ve
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
nam dua » nam da, nam cua, nam mua
dua ban » dia ban, cua ban, qua ban
vai cua » dai cua, hai cua, lai cua

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 (su sach)) ky nang xa hoi. ((hieu van) or (thien van)) nam dua ban thanh vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang xa hoi. ((hieu van) OR (thien van)) nam dua ban thanh vai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky nang xa hoi. ((hieu van) or (thien van)) nam dua ban thanh vai cua viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ky nang xa hoi. ((hieu van) or (thien van)) nam dua ban thanh vai cua viet*.