Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh doi » thanh doi, hanh noi, hang doi
van hanh » van thanh, ban hanh, van anh
thi hang » thi hanh, thi nang, thi hong
chat xuc » chat huu, cam xuc, chao xu
hieu va » lieu va, hieu qua
doi cua » dai cua, hoi cua
xuc van » duc van, luc van, vuc van
cua cau » cua cac, cua chu, cua cay
hieu ve » hieu van
cho hoc » co hoc, khoa hoc
ty nang » ky nang, ty xang, ty hang

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

• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty nang) OR (thi hang)) cho hoc. ((hieu ve) OR (hieu va)) chat xuc van hanh doi cua cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ty nang) or (thi hang)) cho hoc. ((hieu ve) OR (hieu va)) chat xuc van hanh doi cua cau~".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ty nang) or (thi hang)) cho hoc. ((hieu ve) OR (hieu va)) chat xuc van hanh doi cua cau*.