Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
van tuan » van quan, van ban, anh tuan
ky lang » ky dang, ky tang, tay lang
hieu va » lieu va, hieu qua
va pham » van pham, va phat, va phap
duc van » duc va, duc tan, duc manh
tuan vi » quan vi, luan vi, quans vi
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo

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 pham duc van tuan vi ((cua tre) 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 pham duc van tuan vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: doc sach ((ky lang) or (ky nang)) xa hoi. hieu va pham duc van tuan vi ((cua tre) or (cuu tre))*.