Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
qua tham » qua cham, qua than, qua thanh
su triet » su tien, ve triet
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
tay hoi » tay ho, tao hoi, tay thai
xay hoi » xa hoi, cay phoi, gay thoi
ky dang » ky nang, ky danh
su viet » so viet

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 ky dang ((xay hoi) OR (tay hoi)). hieu qua tham thuc van hanh vi ((su triet) OR (su viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky dang ((xay hoi) OR (tay hoi)). hieu qua tham thuc van hanh vi ((su triet) or (su viet))~".
• Adding a wildcard symbol may retrieve word variants: su sach ky dang ((xay hoi) OR (tay hoi)). hieu qua tham thuc van hanh vi ((su triet) or (su viet))*.