Perhaps you should try some spelling variations:
pham sach » pham anh, nam sach, pham hanh
cua triet » cua viet, su triet, va triet
sach van » sach han, sach va, bach van
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty hang, ly nang
hieu va » lieu va, hieu qua
va pham » van pham, va phat, va phap
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: tu sach ((ty nang) OR (ty xang)) xa hoi. hieu va pham sach van hanh vi ((cuu tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty xang)) xa hoi. hieu va pham sach van hanh vi ((cuu tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) OR (ty xang)) xa hoi. hieu va pham sach van hanh vi ((cuu tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) OR (ty xang)) xa hoi. hieu va pham sach van hanh vi ((cuu tre) or (cua triet))*.