Perhaps you should try some spelling variations:
canh tay » canh tac, thanh tay, anh ta
hoc vat » hoc va, hoc viet, thuc vat
hang di » hang doi, hang vi, hang dien
lang ha » long ha
hieu ke » hieu kem, chieu ke, hieu ky
hoc van » hoc dan, hoc va, hoc phan
di cua » dai cua, doi cua, de cua
ke cau » ket cau
cua te » cua tu

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: tu ((xach tay) OR (canh tay)) lang ha noi. hieu ke cau ((hoc van) OR (hoc vat)) hang di cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((xach tay) or (canh tay)) lang ha noi. hieu ke cau ((hoc van) OR (hoc vat)) hang di cua te~".
• Adding a wildcard symbol may retrieve word variants: tu ((xach tay) or (canh tay)) lang ha noi. hieu ke cau ((hoc van) OR (hoc vat)) hang di cua te*.