Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
van cam » van lam, van cau, van dam
hanh di » hanh vi, hanh de, hang di
di cua » dai cua, doi cua, de cua
cua tu » cua tuc, cua su, cua cu
x hoi » o hoi, x ho, 5 hoi

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 ty nang ((x hoi) OR (xa hoi)). hieu ((van cam) or (van nam)) cuu van hanh di cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty nang ((x hoi) OR (xa hoi)). hieu ((van cam) OR (van nam)) cuu van hanh di cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty nang ((x hoi) OR (xa hoi)). hieu ((van cam) or (van nam)) cuu van hanh di cua tu".
• Adding a wildcard symbol may retrieve word variants: thu sach ty nang ((x hoi) OR (xa hoi)). hieu ((van cam) or (van nam)) cuu van hanh di cua tu*.