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
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, de cua, dong cua
co cua » con cua, ca cua, cong 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) OR (co 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) OR (co cua)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (hoc sach)) ky nang x hoi. hieu ve tham thuc xa thanh ((do cua) OR (co 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) OR (co cua)) viet*.