Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
kho tang » cao tang
tu sach » thu sach, su sach, te sach
ky tang » ky nang, ky dang, ky trong
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
thuc va » thuc vat, thuc dan, thuc day
dao va » dao van, do va, cao va

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 ((ky tang) OR (kho tang)) ma hoa. hieu ve pham thuc va van ((dao va) or (tao va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky tang) OR (kho tang)) ma hoa. hieu ve pham thuc va van ((dao va) OR (tao va)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky tang) OR (kho tang)) ma hoa. hieu ve pham thuc va van ((dao va) or (tao va)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky tang) OR (kho tang)) ma hoa. hieu ve pham thuc va van ((dao va) or (tao va)) triet*.