Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
van tuan » van quan, van ban, anh tuan
dinh dau » dinh dat, dinh du, danh dau
dan dinh » dang dinh, doan dinh, van dinh
thuc dan » thuc hanh, hoc dan, thuc vat
van tham » van thanh, van chat, van tai
doc sach » hoc sach, nuoc sach, dac sac
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) OR (doc sach)) ky nang xa hoi. thi ((van tham) or (van tuan)) thuc dan dinh dau cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky nang xa hoi. thi ((van tham) OR (van tuan)) thuc dan dinh dau cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ky nang xa hoi. thi ((van tham) or (van tuan)) thuc dan dinh dau cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) ky nang xa hoi. thi ((van tham) or (van tuan)) thuc dan dinh dau cua tre*.