Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
thuc dan » thuc hanh, hoc dan, thuc vat
dan hanh » dang hanh, dan khanh, dan thanh
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
hanh te » hanh tu, hanh ve, hanh de
y nang » ly nang, v nang, may nang
va cau » van cau, va cac, va dau
cua tu » cua tuc, cua su, cua cu

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