Perhaps you should try some spelling variations:
trinh tai » trinh toan, trinh tu, trinh han
hieu van » hieu va, thien van, lieu va
tinh tai » tinh thai, tinh hai, hinh tai
dang mau » dong mau, dang van, dang su
luc may » truc may, phuc may
van coc » van hoc, van loc, van co
tu sach » thu sach, te sach, tu cach
mau hoi » cau hoi, mai hoi, mau ho
ky dang » ky nang, ky danh
su sach » so sach, vu sach
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 (su sach)) ky dang mau hoi. hieu van coc 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 (su sach)) ky dang mau hoi. hieu van coc luc may ((tinh tai) OR (trinh tai)) cuc tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky dang mau hoi. hieu van coc luc may ((tinh tai) or (trinh tai)) cuc tre*.