Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
ty hang » ly hang, ty xang, thi hang
cho hoc » co hoc, khoa hoc
hieu ve » hieu va, hieu van
cac luc » cau luc, coc luc, cac nuoc
luc van » luoc van, luu van, duc van
ty nang » ky nang, ty xang, ly nang
hanh di » hanh vi, hanh de, hang di
cua cau » cua cac, cua chu, cua cay
ve cac » va cac, vien cac
di cua » dai cua, doi cua, de 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 ((ty nang) or (ty hang)) cho hoc. hieu ve cac luc van hanh di cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty nang) OR (ty hang)) cho hoc. hieu ve cac luc van hanh di cua cau*.