Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
tu sach » thu sach, su sach, te sach
tinh de » tinh da, sinh de, tinh he
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
tuc va » truc va, tuc xa, duc va
de cua » le cua, te cua, dieu cua
x hoi » xa hoi, o hoi, x ho

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. ((hieu ve) or (hieu qua)) cau ((tuc va) or (thuc va)) tinh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu nang x hoi. ((hieu ve) OR (hieu qua)) cau ((tuc va) OR (thuc va)) tinh de cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach thu nang x hoi. ((hieu ve) or (hieu qua)) cau ((tuc va) or (thuc va)) tinh de cua tre*.