Perhaps you should try some spelling variations:
trinh van » trinh han, trinh quan, trinh toan
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, hieu ve
va trinh » van trinh, va tinh, lap trinh
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
cac dat » cai dat, cac dai, cac dac
van cua » vang cua, ban cua, dan cua

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 ky nang cao hoi. ((hieu van) or (lieu va)) ((cac dat) or (cac dan)) va trinh van cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang cao hoi. ((hieu van) OR (lieu va)) ((cac dat) OR (cac dan)) va trinh van cua vat.
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang cao hoi. ((hieu van) or (lieu va)) ((cac dat) or (cac dan)) va trinh van cua vat*.