Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thu nang » thu hang, thu bang, tho nang
hanh vai » hanh vi, hanh va, hanh tai
thi nang » thi cong, ki nang, thi hanh
van hanh » van thanh, ban hanh, van anh
cac luc » cau luc, coc luc, cac nuoc
vai cua » dai cua, hai cua, lai cua
luc van » luoc van, luu van, duc van
hieu ve » hieu van
hieu va » lieu va, hieu qua
cho hoc » co hoc, khoa hoc
cua cau » cua cac, cua chu, cua cay

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