Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
xanh tai » hanh tai, anh tai, vanh tai
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
xanh di » danh di, vanh dai
cuu tre » cua tre, cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang xa hoi. hieu ve ((pham duc) or (cam xuc)) va ((xanh di) OR (xanh tai)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang xa hoi. hieu ve ((pham duc) OR (cam xuc)) va ((xanh di) OR (xanh tai)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang xa hoi. hieu ve ((pham duc) or (cam xuc)) va ((xanh di) OR (xanh tai)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang xa hoi. hieu ve ((pham duc) or (cam xuc)) va ((xanh di) OR (xanh tai)) cuu tre*.