Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
cua cau » cua cac, cua chu, cua can
xuc van » duc van, luc van, vuc van
cac xuc » cam xuc, cac nuoc, chat xuc
hieu ve » hieu va, hieu van
cho hoc » co hoc, khoa hoc
ty tang » tay tang, ty hang, ky tang
cua cay » cua cac
ve cac » va cac, vien cac

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