Perhaps you should try some spelling variations:
kien thuoc » kien thuc, bien thuoc, trien thuoc
thuoc sach » hoc sach, nuoc sach, thuat sach
phan dang » phan dau, phan cong, nhan dan
kinh hoc » hinh hoc, tinh hoc, tin hoc
tu sach » thu sach, su sach, te sach
sach ha » sach nha, sach han, sach xa
ha phan » hoa phan, hai phan, va phan
dang va » dang van, dang vat, hang va
va minh » van minh, vua minh, va kinh

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((kinh hoc) or (sinh hoc)) chuyen đe ky thuat: kien thuoc sach ha phan dang va minh~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((kinh hoc) OR (sinh hoc)) chuyen đe ky thuat: kien thuoc sach ha phan dang va minh.
• Adding a wildcard symbol may retrieve word variants: tu sach ((kinh hoc) or (sinh hoc)) chuyen đe ky thuat: kien thuoc sach ha phan dang va minh*.