Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, le thanh
so sach » so sanh, bo sach, co sach
va tinh » may tinh
van cam » van nam, van lam, van cau
cam tuc » cam xuc, cam tu, nam thuc
sach ky » sac ky, sach y, sach ty
di cua » doi cua, de cua, do cua
nang o » nang co, nang ho, nang ro
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: so sach ky nang o hoi. hieu van cam tuc ((va thanh) or (va tinh)) ((di cua) OR (dai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang o hoi. hieu van cam tuc ((va thanh) OR (va tinh)) ((di cua) OR (dai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang o hoi. hieu van cam tuc ((va thanh) or (va tinh)) ((di cua) OR (dai cua)) te".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang o hoi. hieu van cam tuc ((va thanh) or (va tinh)) ((di cua) OR (dai cua)) te*.