Perhaps you should try some spelling variations:
va trien » va truyen, va thiet, va tuyen
hanh dai » hanh tai, hanh dao, vanh dai
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
tuc va » thuc va, truc va, duc va
ma hoi » mai hoi, ma hoa, me hoi
dai va » mai va
ve cam » ve cham, ve cac, va cam

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