Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
hieu van » hieu va, thien van, lieu va
nang cho » nang chon, ngang cho, nang cao
cho hoc » co hoc, khoa hoc
hieu ve » hieu va
sach ty » sach y, sach tu, sach thu
xuc van » duc van, vuc van, xuc ban
luc van » luoc van, luu van, duc van
ty nang » ky nang, ty xang, ty hang
hanh di » hanh vi, hanh de, hang di
cua cay » cua cac
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ty nang cho hoc. ((hieu ve) or (hieu van)) cac ((xuc van) OR (luc van)) hanh di cua cay~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ty nang cho hoc. ((hieu ve) OR (hieu van)) cac ((xuc van) OR (luc van)) hanh di cua cay*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ty nang cho hoc. ((hieu ve) or (hieu van)) cac ((xuc van) OR (luc van)) hanh di cua cay*".