Perhaps you should try some spelling variations:
thinh duc » tinh duc, trinh duc, trinh duoc
thanh duc » thach duc, than duc, thanh dung
thai cua » than cua, tai cuc, tri cua
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
nang xa » nang x, lang xa, nang ma
sach 2 » sach y
2 nang » v nang

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 2 nang xa hoi. hieu van ((thanh duc) OR (thinh duc)) va hanh ((vai cua) or (thai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach 2 nang xa hoi. hieu van ((thanh duc) OR (thinh duc)) va hanh ((vai cua) OR (thai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach 2 nang xa hoi. hieu van ((thanh duc) OR (thinh duc)) va hanh ((vai cua) or (thai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach 2 nang xa hoi. hieu van ((thanh duc) OR (thinh duc)) va hanh ((vai cua) or (thai cua)) tre*.