Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh tai » thanh tai, hang tai, han tai
tai cuu » tai cuc, tai buu, tai cua
va hanh » van hanh, va thanh, va danh
ky lang » ky nang, ky dang, ky tang
lang ha » long ha
cuu tre » cua tre, cau tren, cau treo
ha hoi » hoa hoi, ha noi, xa hoi
va cam » va cham, va cac, va cao

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