Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thuc dan » thuc hanh, hoc dan, thuc vat
cuu thuc » cuu tac
hanh de » hanh ve, hanh kem
hanh te » hanh tu, hanh ve, hanh he
van cuu » van cau, van chu, van cu
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
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) OR (ty hang)) xa hoi. hieu van cuu thuc dan ((hanh te) or (hanh de)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty nang) OR (ty hang)) xa hoi. hieu van cuu thuc dan ((hanh te) OR (hanh de)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ty nang) OR (ty hang)) xa hoi. hieu van cuu thuc dan ((hanh te) or (hanh de)) cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty nang) OR (ty hang)) xa hoi. hieu van cuu thuc dan ((hanh te) or (hanh de)) cua te*.