Perhaps you should try some spelling variations:
sach nay » sach hay, sach vay, sach nang
sach tay » xach tay, sach hay, sach tai
hanh di » hanh vi, hanh de, hang di
hoc vat » hoc va, hoc viet, thuc vat
hoc van » hoc dan, hoc va, hoc phan
ke chat » ve chat, te chat
hieu ke » hieu kem, chieu ke, hieu ky
lang xa » lang ha, dang xay, lang van
di cua » dai cua, doi cua, de cua
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: thu ((sach tay) OR (sach nay)) lang xa hoi. hieu ke chat ((hoc van) OR (hoc vat)) hanh di cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach tay) or (sach nay)) lang xa hoi. hieu ke chat ((hoc van) OR (hoc vat)) hanh di cua te~".
• Adding a wildcard symbol may retrieve word variants: thu ((sach tay) or (sach nay)) lang xa hoi. hieu ke chat ((hoc van) OR (hoc vat)) hanh di cua te*.