Perhaps you should try some spelling variations:
trinh kxy » trinh ky, trinh ly, trinh ke
kxy thuat » ki thuat, my thuat, ky thua
sach han » sach tham, sach danh, sach nang
toan hoc » toan khoa, van hoc, hoa hoc
tu sach » thu sach, su sach, te sach
thuat o » thuat do
tu hanh » lu hanh, thuc hanh, thi hanh
du hanh » dieu hanh, duy khanh, luu hanh
han ky » hanh ky, than ky, nhan ky
o hoc » co hoc, mo hoc, so hoc

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 han ky thuat o hoc ) or ( ((tu hanh) OR (du hanh)) trinh kxy thuat toan hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach han ky thuat o hoc ) OR ( ((tu hanh) OR (du hanh)) trinh kxy thuat toan hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu sach han ky thuat o hoc ) or ( ((tu hanh) OR (du hanh)) trinh kxy thuat toan hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( tu sach han ky thuat o hoc ) or ( ((tu hanh) OR (du hanh)) trinh kxy thuat toan hoc ))*.