Perhaps you should try some spelling variations:
van thiet » va thiet, dan thiet, can thiet
cam truc » cau truc, nam truc, lam truoc
hanh vu » hanh vi, hanh va, hanh tu
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
qua cam » qua cham, qua cac, qua ca
so sach » co sach, hoc sach
bo sach » co sach, hoc sach
so sanh » do sanh
nang xa » nang x, lang xa, nang ma
vu van » tu van

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) OR (so sanh))) or (bo sach)) ky nang xa hoi. hieu qua cam truc va hanh vu van thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((so sach) OR (so sanh))) OR (bo sach)) ky nang xa hoi. hieu qua cam truc va hanh vu van thiet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((so sach) OR (so sanh))) or (bo sach)) ky nang xa hoi. hieu qua cam truc va hanh vu van thiet*".