Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
vu khach » vu khanh, vu khac, vay khach
hanh di » hanh de, hang di, danh di
cac loc » cac lop, cac toc, cac hoc
hieu va » lieu va, hieu qua
loc va » hoc va, luc va
nang o » nang co, nang ho, nang ro
cua te » cua tu
o hoi » co hoi, o hoc, o hai

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) or (vu khach)) ky nang o hoi. hieu va cac loc va ((hanh di) or (hanh vi)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (vu khach)) ky nang o hoi. hieu va cac loc va ((hanh di) OR (hanh vi)) cua te.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (vu khach)) ky nang o hoi. hieu va cac loc va ((hanh di) or (hanh vi)) cua te*.