Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
cam luc » cam xuc, cau luc
hieu va » hieu qua
cua tre » cua te, cuu tre, cua triet
va lang » va nang, hoa lang
luc va » duc va, tuc va, loc va
v lang » o lang, _ lang, van lang
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 lang) or (va lang)) xa hoi. ((hieu va) OR (lieu va)) cam luc va hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((v lang) OR (va lang)) xa hoi. ((hieu va) OR (lieu va)) cam luc va hanh di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((v lang) or (va lang)) xa hoi. ((hieu va) OR (lieu va)) cam luc va hanh di cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ((v lang) or (va lang)) xa hoi. ((hieu va) OR (lieu va)) cam luc va hanh di cua tre*.