Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
hoc van » hoc dan, hoc va, hoc vat
vu kham » vu khanh
vu cham » va cham, tu cham, qua cham
mang xa » mang may, dang xay, mang cua
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y ((lang xa) or (mang xa)) hoi. hieu ((vu cham) or (vu kham)) hoc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y ((lang xa) OR (mang xa)) hoi. hieu ((vu cham) OR (vu kham)) hoc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach y ((lang xa) or (mang xa)) hoi. hieu ((vu cham) or (vu kham)) hoc van hanh vi cua tre*.