Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ty nang » ty xang, ty hang, ly nang
cho hoc » co hoc, khoa hoc
hieu va » lieu va, hieu qua
cua cau » cua cac, cua chu, cua cay
du van » duy van, duc van, tu van
anh vi » hanh vi, anh ve, anh vu
anh va » hanh va

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 (ky nang)) cho hoc. hieu va cac du van ((anh vi) OR (anh va)) cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty nang) OR (ky nang)) cho hoc. hieu va cac du van ((anh vi) OR (anh va)) cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ty nang) or (ky nang)) cho hoc. hieu va cac du van ((anh vi) OR (anh va)) cua cau*".