Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cao hoi » co hoi, cao hoc, tao hoi
cac dac » cac dan, cac dai, cac bac
va hanh » van hanh, va thanh, va danh
vi cua » vai cua, di cua

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 ty nang ((cao hoi) or (cau hoi)). hieu van ((cac nuoc) or (cac dac)) va hanh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((cao hoi) OR (cau hoi)). hieu van ((cac nuoc) OR (cac dac)) va hanh vi cua vat.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((cao hoi) or (cau hoi)). hieu van ((cac nuoc) or (cac dac)) va hanh vi cua vat*.