Perhaps you should try some spelling variations:
cau theo » cau thi, cau tao
hieu van » hieu va, thien van, lieu va
cau treo » cau tren, cau triet, cau trieu
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
coc thuc » hoc thuc, doc thuc, co thuc
van coc » van hoc, van loc, van co
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, te sach
x hoi » o hoi, x ho, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang ((x hoi) or (xa hoi)). hieu van coc thuc va thanh vi ((cau treo) or (cau theo))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (xa hoi)). hieu van coc thuc va thanh vi ((cau treo) OR (cau theo)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) or (xa hoi)). hieu van coc thuc va thanh vi ((cau treo) or (cau theo))*.