Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
sach tay » xach tay, sach hay, sach nay
tay lang » tai lang, tay tang, tay quang
lang xa » lang ha, dang xay, lang van
van hoc » van hoa
dao hai » dao thai, do hai, dao bai
dai hai » dai han, dai hoi, dai tai
cua tre » cua te, cuu tre, cua triet
nuoc » quoc, duoc, ngoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach tay lang xa hoi. hieu ((va hoc) or (van hoc)) nuoc va ((dao hai) OR (dai hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach tay lang xa hoi. hieu ((va hoc) OR (van hoc)) nuoc va ((dao hai) OR (dai hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach tay lang xa hoi. hieu ((va hoc) or (van hoc)) nuoc va ((dao hai) OR (dai hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat sach tay lang xa hoi. hieu ((va hoc) or (van hoc)) nuoc va ((dao hai) OR (dai hai)) cua tre*.