Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh dai » thanh hai, thanh tai, thanh dat
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
van cac » van cau, van bac, dan cac
van hac » van hoc, van ha, van hai
dac ban » cac ban, dac san, duc ban
y nang » ly nang, v nang, may 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 ((y nang) OR (ky nang)) x ho. hieu ((van cac) or (van hac)) dac ban thanh dai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (ky nang)) x ho. hieu ((van cac) OR (van hac)) dac ban thanh dai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (ky nang)) x ho. hieu ((van cac) or (van hac)) dac ban thanh dai cua viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) OR (ky nang)) x ho. hieu ((van cac) or (van hac)) dac ban thanh dai cua viet*.