Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
ban hanh » ban hang
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
cau tra » ca tra, cau ra, cau truc
ve cac » va cac, vien cac
y nang » ky nang, ly nang, v nang
di cau » da cau, diem cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) OR (toc sach)) y nang xa hoi. hieu ve cac duc ((ban hanh) or (va thanh)) di cau tra~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) y nang xa hoi. hieu ve cac duc ((ban hanh) OR (va thanh)) di cau tra.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) y nang xa hoi. hieu ve cac duc ((ban hanh) or (va thanh)) di cau tra".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) y nang xa hoi. hieu ve cac duc ((ban hanh) or (va thanh)) di cau tra*.