Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
van hanh » van thanh, ban hanh, van anh
hoc sach » hoc sinh, hoc cac, hoc anh
vuc van » duc van, luc van, thuc van
cac vuc » cac nuoc, cac vung, cac cuoc
hieu ve » hieu va, hieu van
cho hoc » co hoc, khoa hoc
ty nang » ky nang, ty hang, ly nang
cua cau » cua cac, cua chu, cua cay
ve cac » va cac, vien cac
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: ((toc sach) or (hoc sach)) ((ty nang) OR (ty xang)) cho hoc. hieu ve cac vuc van hanh vi cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ((ty nang) OR (ty xang)) cho hoc. hieu ve cac vuc van hanh vi cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (hoc sach)) ((ty nang) OR (ty xang)) cho hoc. hieu ve cac vuc van hanh vi cua cau*".