Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
dang xay » dang van, van xay
tinh dan » trinh dan, tinh da, binh dan
tang ma » mang may, tang van
cac duc » cac du, cao duc, cac dac
va tinh » may tinh
dan cua » dan ca, ban cua, dai cua
cua tre » cua te, cuu tre, cua triet

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 y ((tang ma) or (dang xay)) hoi. lieu va cac duc va tinh dan cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y ((tang ma) OR (dang xay)) hoi. lieu va cac duc va tinh dan cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach y ((tang ma) or (dang xay)) hoi. lieu va cac duc va tinh dan cua tre*.