Perhaps you should try some spelling variations:
cac treo » cac tro, cau treo, cac trieu
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
va tuc » va thuc, va tac, ve tuc
x hoi » xa hoi, o hoi, x ho
va tu » va su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang x hoi. hieu qua ((va tuc) OR (va tu)) va hanh va cac treo~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. hieu qua ((va tuc) OR (va tu)) va hanh va cac treo".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu qua ((va tuc) OR (va tu)) va hanh va cac treo*.