Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
vat hanh » vat thanh, van hanh, va hanh
tay lang » tai lang, tay tang, tay quang
tu xach » tu hach, tu sach
hoc vat » hoc va, hoc viet, thuc vat
lang ha » long ha
tu cach » tu cac
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) OR (tu cach)) tay lang ha noi. hieu ((ke cau) OR (ket cau)) hoc vat hanh dai cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu xach) or (tu cach)) tay lang ha noi. hieu ((ke cau) OR (ket cau)) hoc vat hanh dai cua te~".
• Adding a wildcard symbol may retrieve word variants: ((tu xach) or (tu cach)) tay lang ha noi. hieu ((ke cau) OR (ket cau)) hoc vat hanh dai cua te*.