Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van tham » van thanh, van chat, van tai
van tuan » van quan, van ban
thuc dan » thuc hanh, hoc dan, thuc vat
dan danh » van danh, han danh, ban danh
danh dau » lanh dao, hang dau, danh tu
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
dau cua » dai cua, day cua, cau cua
cua tre » cua te, cuu tre, cua triet

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 nang xa hoi. thi ((van tham) or (((van tuan) OR (anh tuan)))) thuc dan danh dau cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. thi ((van tham) OR (((van tuan) OR (anh tuan)))) thuc dan danh dau cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. thi ((van tham) or (((van tuan) OR (anh tuan)))) thuc dan danh dau cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. thi ((van tham) or (((van tuan) OR (anh tuan)))) thuc dan danh dau cua tre*.