Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thu sach » tu sach, thuoc sach, thu hoach
tay lang » tai lang, tay tang, tay quang
manh hoi » manh hai, manh ho, manh hon
hoi cua » hoi chuc
va manh » van manh, va danh, va hanh
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
va cam » va cham, va cac, va cao
ve tai » te tai, de tai, le tai

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) OR (thuat sach)) tay lang xa hoi. hieu ((ve tai) or (va cam)) duc va manh hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuat sach)) tay lang xa hoi. hieu ((ve tai) OR (va cam)) duc va manh hoi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (thuat sach)) tay lang xa hoi. hieu ((ve tai) or (va cam)) duc va manh hoi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (thuat sach)) tay lang xa hoi. hieu ((ve tai) or (va cam)) duc va manh hoi cua tre*.