Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cau tren » cu tren, dau tren, ca tren
cua viet » ca viet, hoa viet, cua vat
hieu vi » hieu voi, hieu va, hieu ve
hanh de » hanh kem
hanh ve » hanh vi, hanh va, hanh kem
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho
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: thu sach y nang x hoi. hieu vi pham duc va ((hanh de) OR (hanh ve)) ((cau tren) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang x hoi. hieu vi pham duc va ((hanh de) OR (hanh ve)) ((cau tren) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang x hoi. hieu vi pham duc va ((hanh de) OR (hanh ve)) ((cau tren) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang x hoi. hieu vi pham duc va ((hanh de) OR (hanh ve)) ((cau tren) or (cua viet))*.