Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
vai cua » dai cua, hai cua, lai cua
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
va lang » va nang, hoa lang
va cam » va cham, va cac, va cao
luc va » tuc va, loc va
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: ((te sach) or (toc sach)) va lang xa hoi. hieu va cam ((luc va) or (duc va)) hanh vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) va lang xa hoi. hieu va cam ((luc va) OR (duc va)) hanh vai cua te.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) va lang xa hoi. hieu va cam ((luc va) or (duc va)) hanh vai cua te*.