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