Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cham tuc » nham thuc, pham thuc, tham thuc
hieu va » hieu qua
va danh » va dinh, va dan, va hanh
danh di » danh du, xanh di, danh dien
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
v nang » va nang, vu nang, van nang
sach v » sach va, sach y, sach 2
tuc va » thuc va, truc va, tuc xa
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach v nang x hoi. ((hieu va) OR (lieu va)) cham tuc va danh di ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v nang x hoi. ((hieu va) OR (lieu va)) cham tuc va danh di ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach v nang x hoi. ((hieu va) OR (lieu va)) cham tuc va danh di ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: toc sach v nang x hoi. ((hieu va) OR (lieu va)) cham tuc va danh di ((cua tre) or (cuu tre))*.