Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
su sach » so sach, vu sach
lang xa » lang ha, dang xay, lang van
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
cu tren » tu tren, dua tren
y lang » o lang, _ lang, tay lang
hieu v » hieu va, hieu ve, hieu 2
v pham » vi pham, d pham

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y lang xa hoi. hieu v pham duc va hanh vi ((cua tre) or (((dau tren) or (cu tren))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y lang xa hoi. hieu v pham duc va hanh vi ((cua tre) OR (((dau tren) OR (cu tren)))).
• Adding a wildcard symbol may retrieve word variants: su sach y lang xa hoi. hieu v pham duc va hanh vi ((cua tre) or (((dau tren) or (cu tren))))*.