Perhaps you should try some spelling variations:
toan dinh » tran dinh, toan kinh, doan dinh
cac khien » cac chien, cac phien, cach thien
khien hoc » nhiet hoc, dien hoc
dinh cac » tinh cach, dinh chuc, dinh chau
sach xin » sach kinh, sach tien, sach xa
cac khoa » cac khoan, dac khoa, cao khoa
cac khoi » cac thoi, cac khoan, cach thoi
vu sach » vu bach, su sach, vu khach

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( thuat toan dinh cac khien hoc ) OR ( vu sach xin ((cac khoa) OR (cac khoi)) hoc ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( thuat toan dinh cac khien hoc ) or ( vu sach xin ((cac khoa) OR (cac khoi)) hoc ))~".
• Adding a wildcard symbol may retrieve word variants: (( thuat toan dinh cac khien hoc ) or ( vu sach xin ((cac khoa) OR (cac khoi)) hoc ))*.