Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
hoc sach » hoc sinh, hoc cac, hoc anh
xa thanh » va thanh, ha thanh, ta thanh
thanh do » thanh de, thanh pho, thanh hoa
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
ve tham » va tham, ve cham, vi tham
thuc xa » thuc xay, tuc xa, thuc va
do cua » doi cua, co cua, de cua
x hoi » xa hoi, o hoi, x ho

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 (hoc sach)) ky nang x hoi. hieu ve tham thuc xa thanh do cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (hoc sach)) ky nang x hoi. hieu ve tham thuc xa thanh do cua viet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (hoc sach)) ky nang x hoi. hieu ve tham thuc xa thanh do cua viet*.