Perhaps you should try some spelling variations:
thanh lap » thanh san, phan lap, thanh hai
cua viet » ca viet, hoa viet, cua vat
thu sach » thuat sach, thuoc sach, thu hoach
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
cac duc » cac du, cac dac, cac nuoc
lap cua » lai cua, tap cua, lam cua
cao duc » dao duc, cao suc, giao duc
tu sach » su sach, te sach, tu cach
nang o » nang co, nang ho, nang ro
o hai » co hai, so hai, o lai

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) or (thu sach)) ky nang o hai. hieu van ((cac duc) OR (cao duc)) va thanh lap cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang o hai. hieu van ((cac duc) OR (cao duc)) va thanh lap cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky nang o hai. hieu van ((cac duc) OR (cao duc)) va thanh lap cua viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang o hai. hieu van ((cac duc) OR (cao duc)) va thanh lap cua viet*.