Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
dan hanh » dang hanh, dan khanh, dan thanh
hieu van » thien van, lieu va
cuu thuc » cuu tac
thuc dan » thuc hanh, hoc dan, thuc vat
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
hanh te » hanh tu, hanh ve, hanh de
te cua » tue cua, le cua, de cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ty nang xa hoi. ((((hieu van) OR (hieu ve))) or (hieu va)) cuu thuc dan hanh te cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty nang xa hoi. ((((hieu van) OR (hieu ve))) OR (hieu va)) cuu thuc dan hanh te cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty nang xa hoi. ((((hieu van) OR (hieu ve))) or (hieu va)) cuu thuc dan hanh te cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ty nang xa hoi. ((((hieu van) OR (hieu ve))) or (hieu va)) cuu thuc dan hanh te cua te*.