Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thu sach » thuat sach, thuoc sach, thu hoach
tinh vai » tinh va, tinh hai, tinh bai
van dat » van dao, van dau, dan dat
vai cua » dai cua, hai cua, lai cua
va tinh » may tinh
tu sach » su sach, te sach, tu cach
lang xa » lang ha, dang xay, lang van
ty lang » tay lang, ty xang, ty hang
cua chu » sua chua

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) OR (thu sach)) ty lang xa hoi. hieu van dat (nuoc or duoc) va tinh vai cua chu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ty lang xa hoi. hieu van dat (nuoc OR duoc) va tinh vai cua chu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ty lang xa hoi. hieu van dat (nuoc or duoc) va tinh vai cua chu".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ty lang xa hoi. hieu van dat (nuoc or duoc) va tinh vai cua chu*.