Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
lang hai » lang chai, lang thai, lang ha
hai cua » thai cua, dai cua, hoi cua
va lang » va nang, hoa lang
cam duc » cam xuc, cao duc, pham duc
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
va cam » va cham, va cac, va cao
cua te » cua tu
me hoi » le hoi
v nang » va nang, vu nang, van nang

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)) v nang ((me hoi) or (mai hoi)). hieu va cam duc va lang hai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) v nang ((me hoi) OR (mai hoi)). hieu va cam duc va lang hai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) v nang ((me hoi) or (mai hoi)). hieu va cam duc va lang hai cua te".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) v nang ((me hoi) or (mai hoi)). hieu va cam duc va lang hai cua te*.