Perhaps you should try some spelling variations:
sach tranh » canh tranh
tranh khoi » trinh khoi, trinh khoa, tran khoa
khoi thuat » ki thuat, hoc thuat
sach danh » sach dao, sach dung, sach kinh
kxy thuat » ky thuat, ki thuat, my thuat
danh kxy » hanh ky, dan ky
tu sach » thu sach, su sach, te sach
thuat o » thuat do
o hoc » co hoc, mo hoc, so hoc
toan » tran

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 danh kxy thuat o hoc ) or ( tu sach tranh khoi thuat toan khoa ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach danh kxy thuat o hoc ) OR ( tu sach tranh khoi thuat toan khoa ))*.