Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
tu sach » thu sach, su sach, te sach
cua tre » cuu tre, cua triet, dua tren
dau tai » dai tai, dat tai, da tai
sach ly » sach y, sach lo, sach ty
hieu ve » hieu va, hieu van
ly nang » ky nang, ly hang, ly vang
mai hoi » dai hoi, lai hoi, mai doi
ve cam » ve cham, ve cac, va cam
xuc va » duc va, tuc va, luc va
va dau » va dao
cua te » cua tu

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 ly nang ((mai hoi) or (mai khoi)). hieu ve cam xuc va dau tai ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ly nang ((mai hoi) OR (mai khoi)). hieu ve cam xuc va dau tai ((cua tre) OR (cua te))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ly nang ((mai hoi) or (mai khoi)). hieu ve cam xuc va dau tai ((cua tre) OR (cua te))*".