Perhaps you should try some spelling variations:
trinh tai » trinh toan, trinh tu, trinh han
hieu van » hieu va, thien van, lieu va
vu khach » vu khanh, vu khac, vay khach
dang mau » dong mau, dang van, dang su
tinh tai » tinh thai, tinh hai, hinh tai
cac luc » cau luc, coc luc, cac nuoc
luc may » truc may, phuc may
tu sach » thu sach, su sach, te sach
van cac » van hac, van cau, van bac
mau hoi » cau hoi, mai hoi, mau ho
ky dang » ky nang, ky danh
cuc tre » duc tre, cua tre, cuu tre

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) or (vu khach)) ky dang mau hoi. hieu van cac luc may ((tinh tai) or (trinh tai)) cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (vu khach)) ky dang mau hoi. hieu van cac luc may ((tinh tai) OR (trinh tai)) cuc tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (vu khach)) ky dang mau hoi. hieu van cac luc may ((tinh tai) or (trinh tai)) cuc tre*.