Perhaps you should try some spelling variations:
tham thuc » nham thuc, tam thuc, thai thuc
pham thuc » phap thuc, pham chuc, nham thuc
sach dao » lanh dao
dao tang » dao trang, cao tang, dam tang
danh dao » doanh dao, lanh dao, danh dau
tu sach » thu sach, su sach, te sach
tang xa » trang xa, tang ma, lang xa
hieu ve » hieu va, hieu van
va danh » va dinh, va dan, va hanh
dao va » dao van, tao va, do va
thiet » thieu

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 dao tang xa hoi. hieu ve ((tham thuc) or (pham thuc)) va danh dao va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach dao tang xa hoi. hieu ve ((tham thuc) OR (pham thuc)) va danh dao va thiet.
• Adding a wildcard symbol may retrieve word variants: tu sach dao tang xa hoi. hieu ve ((tham thuc) or (pham thuc)) va danh dao va thiet*.