Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, nam duoc
cua tre » cua te, cua triet, dua tren
cuu 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: su sach ky nang xa hoi. hieu va ((cam duc) or (pham duc)) van hanh vi ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang xa hoi. hieu va ((cam duc) OR (pham duc)) van hanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang xa hoi. hieu va ((cam duc) or (pham duc)) van hanh vi ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang xa hoi. hieu va ((cam duc) or (pham duc)) van hanh vi ((cua tre) OR (cuu tre))*.