Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
sach ngan » sach ngon, sach nha, sach han
thua toan » thuat toan, cua toan, hoa toan
toan hoc » toan khoa, van hoc, hoa hoc
tu sach » thu sach, su sach, te sach
ngan ky » nganh ky, nhan ky, ngan hay
thuat o » thuat do
tu hanh » du hanh, lu hanh, thuc hanh
ky thua » ky thu, kxy thuat, ki thuat
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 ngan ky thuat o hoc ) or ( tu hanh trinh ky thua toan hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach ngan ky thuat o hoc ) OR ( tu hanh trinh ky thua toan hoc )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach ngan ky thuat o hoc ) or ( tu hanh trinh ky thua toan hoc ))*.