Perhaps you should try some spelling variations:
thuc giai » thuoc giao, hoc giai, thue gia
thuc thai » thuc pham, toc thai, thuc thuc
va triet » va thiet, va trien, ve triet
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
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: so sach ky nang xa hoi. hieu va cac ((thuc giai) OR (thuc thai)) hanh vi ((cuu tre) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang xa hoi. hieu va cac ((thuc giai) OR (thuc thai)) hanh vi ((cuu tre) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang xa hoi. hieu va cac ((thuc giai) OR (thuc thai)) hanh vi ((cuu tre) or (va triet))".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang xa hoi. hieu va cac ((thuc giai) OR (thuc thai)) hanh vi ((cuu tre) or (va triet))*.