Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
toc sach » hoc sach, doc sach, thuoc sach
va thuat » ky thuat, ki thuat, va thuc
van tham » van tuan, van chat, van tai
danh tai » doanh tai, dinh tai, hanh tai
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
va danh » va dinh, va dan, va hanh
buu tre » cuu tre

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky lang xa hoi. hieu ((va thuat) or (((van tham) or (van thanh)))) duc va danh tai buu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang xa hoi. hieu ((va thuat) OR (((van tham) OR (van thanh)))) duc va danh tai buu tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang xa hoi. hieu ((va thuat) or (((van tham) or (van thanh)))) duc va danh tai buu tre*.