Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
thi hanh » thi thanh
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 nang
van dau » van dao, phan dau
dau cua » dai cua, day cua, cau cua
cua tre » cua te, cuu tre, cua triet
tuc ca » tuc cac, tuc cua, tuc xa
ca van » cac van, cao van, can 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) OR (thi hanh)))) cham tuc ca van dau cua 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) OR (thi hanh)))) cham tuc ca van dau cua 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) OR (thi hanh)))) cham tuc ca van dau cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky nang xa hoi. ((thien van) or (((thi van) OR (thi hanh)))) cham tuc ca van dau cua tre*.