Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hang doi » hang di, hang loi, huong doi
cau tren » cu tren, dau tren, ca tren
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va hang » van hang, va nang, va lang
cuu tre » cua tre, cau treo
cac tu » cac thu, cach tu, cac du

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. hieu va cac tu va hang doi ((cuu tre) OR (cau tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. hieu va cac tu va hang doi ((cuu tre) OR (cau tren))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu va cac tu va hang doi ((cuu tre) OR (cau tren))*.