Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
hieu van » thien van, lieu va
thuc dan » thuc hanh, hoc dan, thuc vat
dan danh » van danh, han danh, ban danh
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
xang xa » lang xa, mang xa, ang xa
hieu va » lieu va, hieu qua
danh di » danh du, xanh di, danh dien
di hoa » dai hoa, doi hoa, do hoa

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty xang xa hoi. ((((hieu ve) OR (hieu va))) OR (hieu van)) tham thuc dan danh di hoa viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty xang xa hoi. ((((hieu ve) OR (hieu va))) or (hieu van)) tham thuc dan danh di hoa viet~".
• Adding a wildcard symbol may retrieve word variants: su sach ty xang xa hoi. ((((hieu ve) OR (hieu va))) or (hieu van)) tham thuc dan danh di hoa viet*.