Perhaps you should try some spelling variations:
dung tren » dung trong, dung trung
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc
duc van » duc va, duc tan, duc manh
y lang » o lang, _ lang, tay lang
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y lang xa hoi. hieu van cau duc van hanh vi ((((dua tren) or (dung tren))) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y lang xa hoi. hieu van cau duc van hanh vi ((((dua tren) OR (dung tren))) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: tu sach y lang xa hoi. hieu van cau duc van hanh vi ((((dua tren) or (dung tren))) or (cua te))*.