Perhaps you should try some spelling variations:
kien thuoc » kien thuc, bien thuoc, trien thuoc
thuoc sach » hoc sach, nuoc sach, thuat sach
phan xuong » phan cong
xuong hay » huong hay, xuong hat, xuong hoan
tien hoc » tin hoc, tien hoa, tien hon
dien hoc » dien hoa, khien hoc, tin hoc
sach hoa » sach ha, sach hoi, bach hoa
hoa phan » hoa dan, co phan
hay tinh » may tinh, ha tinh, huy tinh
tu sach » thu sach, su sach, te sach

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 ((tien hoc) or (dien hoc)) chuyen đe ky thuat: kien thuoc sach hoa phan xuong hay tinh~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((tien hoc) OR (dien hoc)) chuyen đe ky thuat: kien thuoc sach hoa phan xuong hay tinh.
• Adding a wildcard symbol may retrieve word variants: tu sach ((tien hoc) or (dien hoc)) chuyen đe ky thuat: kien thuoc sach hoa phan xuong hay tinh*.