Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van tuan » van quan, van ban, anh tuan
mai khoi » mai khoa, tai khoa, cac khoi
cua tre » cuu tre, cua triet, dua tren
luc van » luoc van, luu van, duc van
cau luc » cau truc, cau phuc
hieu ve » hieu va, hieu van
mai hoi » dai hoi, lai hoi, mai doi
sach v » sach va, sach y, sach 2
ve cau » ke cau, va cau, ve cac
v nang » va nang, vu nang, van nang
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: toc sach v nang ((mai hoi) OR (mai khoi)). hieu ve cau luc van tuan le ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v nang ((mai hoi) OR (mai khoi)). hieu ve cau luc van tuan le ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach v nang ((mai hoi) OR (mai khoi)). hieu ve cau luc van tuan le ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: toc sach v nang ((mai hoi) OR (mai khoi)). hieu ve cau luc van tuan le ((cua tre) or (cua te))*.