Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
dua ban » dia ban, cua ban, qua ban
hanh ki » hanh vi, hanh kien, thanh kim
hanh ky » hanh kem
su viet » so viet
va cam » va cham, va cao, va cai

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