Perhaps you should try some spelling variations:
sach trien » sach tien, sach tren, sach thieu
trien hoat » tien hoa
hoat huyen » hoa huyen, dat huyen, hoi huyen
thuoc sach » hoc sach, nuoc sach, thuat sach
khoa than » khoa luan, hoa thai, hoa tan
than cung » phan cung, thay cung, tham cung
cung may » dung may, cong may, cung hay
tu sach » thu sach, su sach, te sach
tinh » trinh, dinh, minh

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 trien hoat huyen đe ky thuat: kien ((thuoc sach) or (cuoc cach)) khoa than cung may tinh~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach trien hoat huyen đe ky thuat: kien ((thuoc sach) OR (cuoc cach)) khoa than cung may tinh.
• Adding a wildcard symbol may retrieve word variants: tu sach trien hoat huyen đe ky thuat: kien ((thuoc sach) or (cuoc cach)) khoa than cung may tinh*.