Perhaps you should try some spelling variations:
doc thuc » hoc thuc, do thuc, hoc thuoc
lang van » dang van, tang van, hoang van
coc thuc » hoc thuc, co thuc, cong thuc
vu sach » vu bach, su sach, vu khach
tinh vi » trinh vi, tinh voi, tinh va
va tinh » may tinh
hieu ve » hieu va, hieu van
van hoc » van hoa
ky lang » ky nang, ky dang, ky tang
bo sach » co sach, hoc sach
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (bo sach)) ky lang van hoc. hieu ve ((coc thuc) OR (doc thuc)) va tinh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (bo sach)) ky lang van hoc. hieu ve ((coc thuc) OR (doc thuc)) va tinh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (bo sach)) ky lang van hoc. hieu ve ((coc thuc) OR (doc thuc)) va tinh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (bo sach)) ky lang van hoc. hieu ve ((coc thuc) OR (doc thuc)) va tinh vi cua tre*.