Perhaps you should try some spelling variations:
thuc dan » hoc dan, thuc vat
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
thi van » thi lan, thi hanh, thi nang
hanh di » hanh vi, hanh de, hang di
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
di va » dai va, di vao, doi va

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 ((y nang) OR (v nang)) xa hoi. thi van nam ((thuc dan) or (thuc hanh)) hanh di va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (v nang)) xa hoi. thi van nam ((thuc dan) OR (thuc hanh)) hanh di va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (v nang)) xa hoi. thi van nam ((thuc dan) or (thuc hanh)) hanh di va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) OR (v nang)) xa hoi. thi van nam ((thuc dan) or (thuc hanh)) hanh di va triet*.