Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
tinh lai » tinh lao, tinh hai, minh lai
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
cua tre » cua te, cua triet, dua tren
va tinh » may tinh
van cac » van hac, van cau, van bac
cuu tre » cau tren, cau treo
cac xuc » cam xuc, cac nuoc, chat xuc
xuc va » duc va, tuc va, luc va
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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 thu nang ((x hoi) or (o hoi)). hieu van cac xuc va tinh lai ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu nang ((x hoi) OR (o hoi)). hieu van cac xuc va tinh lai ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach thu nang ((x hoi) or (o hoi)). hieu van cac xuc va tinh lai ((cua tre) or (cuu tre))*.