Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
sach hay » sach han, sach ha, sach nay
hay lang » ha lang, tay lang, nhan lang
minh hai » minh khai, tinh hai, minh chau
manh hai » lanh hai, thanh hai, van hai
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
ve cai » va cai, ve cac, ve tai
va cam » va cham, va cac, va cao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach hay lang xa hoi. hieu ((ve cai) or (va cam)) duc va ((manh hai) or (minh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach hay lang xa hoi. hieu ((ve cai) OR (va cam)) duc va ((manh hai) OR (minh hai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach hay lang xa hoi. hieu ((ve cai) or (va cam)) duc va ((manh hai) or (minh hai)) cua tre*.