Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
tang van » dang van, hoang van, trong van
hieu van » hieu va, thien van, lieu va
hoc viet » hoc hien
su sach » so sach, vu sach
van hoc » van hoa
hieu ve » hieu va
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
y tang » ky tang, 6 tang, 7 tang
vi hoc » li hoc, va hoc

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 y tang van hoc. ((hieu ve) OR (hieu van)) tham thuc va hanh vi hoc viet~.
• Adding a wildcard symbol may retrieve word variants: su sach y tang van hoc. ((hieu ve) or (hieu van)) tham thuc va hanh vi hoc viet*.