Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
ly nang » ky nang, ly hang, ly vang
cam dua » ca dua, cay dua, chay dua
dua ban » dia ban, cua ban, qua ban
danh va » doanh va, anh va, dan va
hanh va » hang va, hanh vi
su viet » so viet
y nang » ky nang, v nang, may nang
va cam » va cham, va cac, va cao

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