Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thien van » thi van
cao hoi » cau hoi, co hoi, cao hoc
hac duc » hoc duc, thach duc, pham duc
va hanh » van hanh, va thanh, va danh
ca viet » va viet, co viet, hoa viet
y nang » ly nang, v nang, may nang
ha duc » ho duc, ha dac, xa duc
vi ca » vit ca, li ca, va ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ((y nang) or (ky nang)) cao hoi. thien van ((hac duc) OR (ha duc)) va hanh vi ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((y nang) OR (ky nang)) cao hoi. thien van ((hac duc) OR (ha duc)) va hanh vi ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((y nang) or (ky nang)) cao hoi. thien van ((hac duc) OR (ha duc)) va hanh vi ca viet".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((y nang) or (ky nang)) cao hoi. thien van ((hac duc) OR (ha duc)) va hanh vi ca viet*.