Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » thien van, lieu va
vat hanh » vat thanh, van hanh, va hanh
cam thuc » am thuc, nam thuc, cam thu
hanh va » hang va, hanh vi
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
chu tre » cho tre, chu tri, cuu tre
va chu » va che, va cau, va chi

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. ((((hieu ve) or (hieu va))) or (hieu van)) cam thuc vat hanh va chu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ty nang xa hoi. ((((hieu ve) OR (hieu va))) OR (hieu van)) cam thuc vat hanh va chu tre.
• Adding a wildcard symbol may retrieve word variants: hoc sach ty nang xa hoi. ((((hieu ve) or (hieu va))) or (hieu van)) cam thuc vat hanh va chu tre*.