Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
duc van » duc va, duc tan, duc manh
va cam » va cham, va cao, va cai
o lang » hoa lang, hoi lang
v lang » va lang, _ lang, van 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: toc sach ((v lang) or (o lang)) xa hoi. hieu ((va cam) or (va cac)) duc van hanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((v lang) OR (o lang)) xa hoi. hieu ((va cam) OR (va cac)) duc van hanh dai cua te.
• Adding a wildcard symbol may retrieve word variants: toc sach ((v lang) or (o lang)) xa hoi. hieu ((va cam) or (va cac)) duc van hanh dai cua te*.