Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
hieu van » hieu va, thien van, lieu va
chat xuc » chat huu, cam xuc, chao xu
nang cho » nang chon, ngang cho, nang cao
hieu ve » hieu va
cho hoc » co hoc, khoa hoc
sach ty » sach y, sach tu, sach thu
xuc van » duc van, luc van, vuc van
ty nang » ky nang, ty xang, ty hang
hanh di » hanh vi, hang di, danh di
hanh de » hanh ve, hanh kem
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: doc sach ty nang cho hoc. ((hieu ve) or (hieu van)) chat xuc van ((hanh di) OR (hanh de)) cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ty nang cho hoc. ((hieu ve) OR (hieu van)) chat xuc van ((hanh di) OR (hanh de)) cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ty nang cho hoc. ((hieu ve) or (hieu van)) chat xuc van ((hanh di) OR (hanh de)) cua cau*".