Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
vat hanh » vat thanh, van hanh, va hanh
cau thuc » cau truc, cuu thuc, can thuc
hieu van » thien van, lieu va, hieu ve
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
hieu va » lieu va, hieu qua
hanh te » hanh tu, hanh ve, hanh de
te cua » tue cua, le cua, de cua
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) OR (thuoc sach)) ty nang xa hoi. ((hieu van) or (hieu va)) cau thuc vat hanh te cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) ty nang xa hoi. ((hieu van) OR (hieu va)) cau thuc vat hanh te cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (thuoc sach)) ty nang xa hoi. ((hieu van) or (hieu va)) cau thuc vat hanh te cua te".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (thuoc sach)) ty nang xa hoi. ((hieu van) or (hieu va)) cau thuc vat hanh te cua te*.