Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cham tuc » nham thuc, pham thuc, tham thuc
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
thi van » thi lan, thi hanh, thi nang
cao van » cac van, dao van, cao dang
dau cuu » dau cua, dau cuoi
cuu tre » cua tre, cau tren, cau treo
ca van » cac van, can van, cap van

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ky nang xa hoi. ((thien van) or (thi van)) cham tuc ((ca van) OR (cao van)) dau cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky nang xa hoi. ((thien van) OR (thi van)) cham tuc ((ca van) OR (cao van)) dau cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky nang xa hoi. ((thien van) or (thi van)) cham tuc ((ca van) OR (cao van)) dau cuu tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky nang xa hoi. ((thien van) or (thi van)) cham tuc ((ca van) OR (cao van)) dau cuu tre*.