Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hang vai » hang tai, hang vi, hang vat
hang hai » hoang hai, hang tai, thanh hai
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
cac duc » cac du, cao duc, cac dac
cua tre » cua te, cuu tre, cua triet

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 ty nang xa hoi. lieu va cac duc tan ((((hang vai) OR (hang hai))) or (hang va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ty nang xa hoi. lieu va cac duc tan ((((hang vai) OR (hang hai))) OR (hang va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ty nang xa hoi. lieu va cac duc tan ((((hang vai) OR (hang hai))) or (hang va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach ty nang xa hoi. lieu va cac duc tan ((((hang vai) OR (hang hai))) or (hang va)) cua tre*.