Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach thi » sach thu, sach tai, sach thieu
thi nang » thi cong, ki nang, thi hanh
nang cho » nang chon, ngang cho, nang cao
hanh doi » thanh doi, hanh noi, hang doi
cho hoc » co hoc, khoa hoc
hieu ve » hieu van
hieu va » lieu va, hieu qua
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
doi cua » dai cua, hoi 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 thi nang cho hoc. ((hieu ve) or (hieu va)) cac ((xuc van) OR (duc van)) hanh doi cua cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach thi nang cho hoc. ((hieu ve) OR (hieu va)) cac ((xuc van) OR (duc van)) hanh doi cua cac*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach thi nang cho hoc. ((hieu ve) or (hieu va)) cac ((xuc van) OR (duc van)) hanh doi cua cac*".