Perhaps you should try some spelling variations:
chanh trinh » hanh trinh, thanh trinh, canh tranh
sach ngan » sach ngon, sach nha, sach han
trinh kxy » trinh ky, trinh ly, trinh ke
kxy thuat » ky thuat, ki thuat, my thuat
va thuat » ky thuat, ki thuat, va thuc
tu chanh » tu hanh, tu thanh, tu chung
tu sach » thu sach, su sach, te sach
ngan va » ngan van, nhan va, ngay va
mo hoc » mon hoc, co hoc
o hoc » co hoc, so hoc, y 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 ngan va thuat ((o hoc) OR (mo hoc)) ) or ( tu chanh trinh kxy thuat toan khoa ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach ngan va thuat ((o hoc) OR (mo hoc)) ) OR ( tu chanh trinh kxy thuat toan khoa ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu sach ngan va thuat ((o hoc) OR (mo hoc)) ) or ( tu chanh trinh kxy thuat toan khoa ))*".