Perhaps you should try some spelling variations:
chat duc » chat xuc, chat doc, chet duoc
che quoc » che duoc, he quoc, che thuoc
thu sach » thuat sach, thuoc sach, thu hoach
hanh lai » hanh lam, hanh tai, thanh lap
hieu van » hieu va, thien van, lieu va
lai cua » dai cua, hai cua, lai chau
va hanh » van hanh, va thanh, va danh
tu sach » su sach, te sach, tu cach
xang xa » lang xa, mang xa, ang xa
cua tu » cua tuc, cua su, cua cu

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 xang xa hoi. hieu van ((chat duc) or (che quoc)) va hanh lai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ty xang xa hoi. hieu van ((chat duc) OR (che quoc)) va hanh lai cua tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ty xang xa hoi. hieu van ((chat duc) or (che quoc)) va hanh lai cua tu".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ty xang xa hoi. hieu van ((chat duc) or (che quoc)) va hanh lai cua tu*.