Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va nham » va cham, va tham, va nha
cua tre » cua te, cuu tre, cua triet
thu va » thuc va, thue va, thu ha
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (toc sach)) ky nang xa hoi. hieu va nham ((thu va) OR (tu va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (toc sach)) ky nang xa hoi. hieu va nham ((thu va) OR (tu va)) hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (toc sach)) ky nang xa hoi. hieu va nham ((thu va) OR (tu va)) hanh vi cua tre*".