Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
manh dai » manh hai, vanh dai, manh khai
lang van » dang van, tang van, hoang van
sach nay » sach hay, sach vay, sach nang
va manh » van manh, va danh, va hanh
lang xa » lang ha, dang xay
cua tre » cua te, cuu tre, cua triet
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 nay ((lang xa) OR (lang van)) hoi. hieu ((ve cai) or (va cam)) duc va manh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach nay ((lang xa) OR (lang van)) hoi. hieu ((ve cai) OR (va cam)) duc va manh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach nay ((lang xa) OR (lang van)) hoi. hieu ((ve cai) or (va cam)) duc va manh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach nay ((lang xa) OR (lang van)) hoi. hieu ((ve cai) or (va cam)) duc va manh dai cua tre*.