Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh dai » hanh tai, hanh dao, vanh dai
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
phuc van » thuc van, phuc va, chuc van
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
ve cac » va cac, vien cac
ve cau » ke cau, va cau, le cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (toc sach)) ky lang xa hoi. hieu ((ve cau) or (ve cac)) phuc van hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (toc sach)) ky lang xa hoi. hieu ((ve cau) OR (ve cac)) phuc van hanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (toc sach)) ky lang xa hoi. hieu ((ve cau) or (ve cac)) phuc van hanh dai cua tre*.