Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
doc sach » hoc sach, toc sach, nuoc sach
van tuan » van quan, van ban, anh tuan
duc van » duc va, duc tan, duc manh
tuan vi » quan vi, luan vi, quans vi
cam duc » cam xuc, cao duc, pham duc
hieu va » lieu va, hieu qua
ky lang » ky dang, ky tang, tay lang
cuu tre » cua tre, cau tren, cau treo
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ((ky lang) or (ky nang)) xa hoi. hieu va cam duc van tuan vi ((cua triet) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ((ky lang) OR (ky nang)) xa hoi. hieu va cam duc van tuan vi ((cua triet) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: doc sach ((ky lang) or (ky nang)) xa hoi. hieu va cam duc van tuan vi ((cua triet) or (cuu tre))*.