Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
chat xuc » chat huu, cam xuc, chao xu
hieu va » lieu va, hieu qua
hanh di » hanh vi, hanh de, hang di
xuc van » duc van, luc van, vuc van
cua tuc » cua duc, cua tu, cua thuoc
hieu ve » hieu van
ma hoi » mai hoi, xa hoi, ma hoa
_ sang » _ san
v sang » va sang, ve sang, van sang
di cua » dai cua, doi cua, de cua

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 sang) or (_ sang)) ma hoi. ((hieu ve) OR (hieu va)) chat xuc van hanh di cua tuc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((v sang) OR (_ sang)) ma hoi. ((hieu ve) OR (hieu va)) chat xuc van hanh di cua tuc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((v sang) or (_ sang)) ma hoi. ((hieu ve) OR (hieu va)) chat xuc van hanh di cua tuc".
• Adding a wildcard symbol may retrieve word variants: toc sach ((v sang) or (_ sang)) ma hoi. ((hieu ve) OR (hieu va)) chat xuc van hanh di cua tuc*.