Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
toc sach » hoc sach, doc sach, nuoc sach
hanh lai » hanh lam, hanh tai, thanh lap
van hanh » van thanh, ban hanh, van anh
lai cua » dai cua, hai cua, lai chau
duc van » duc va, duc tan, duc manh
cac duc » cac du, cao duc, cac dac
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
bang xa » bang va, mang xa, ang xa
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: ((toc sach) or (thuoc sach)) thu ((bang xa) OR (lang xa)) hoi. hieu va cac duc van hanh lai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (thuoc sach)) thu ((bang xa) OR (lang xa)) hoi. hieu va cac duc van hanh lai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (thuoc sach)) thu ((bang xa) OR (lang xa)) hoi. hieu va cac duc van hanh lai cua te".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (thuoc sach)) thu ((bang xa) OR (lang xa)) hoi. hieu va cac duc van hanh lai cua te*.