Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va gianh » va gian, van giang, va giai
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hieu ve » hieu va, hieu van
cam duc » cam xuc, cao duc, pham duc
lai cua » dai cua, hai cua, thai cua
ve cam » ve cham, ve cac, va cam

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)) ky tang xa hoi. hieu ve cam duc va gianh ((lai cua) or (lai chau)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky tang xa hoi. hieu ve cam duc va gianh ((lai cua) OR (lai chau)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky tang xa hoi. hieu ve cam duc va gianh ((lai cua) or (lai chau)) tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky tang xa hoi. hieu ve cam duc va gianh ((lai cua) or (lai chau)) tre*.