Perhaps you should try some spelling variations:
van hoang » van hoan, quan hoang, tran hoang
thu sach » tu sach, thuat sach, thuoc sach
hoang di » hoang dai, hoang de, hang di
sach ky » sac ky, sach y, sach ty
luc van » luoc van, luu van, duc van
su tien » su kien, su hien, tu tieng
ve cham » va cham, ve chat, vu cham
va cam » va cham, va cac, va cao
ma hoi » mai hoi, ma hoa, me hoi
di su » doi su, ki su, da su

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang ((ma hoi) OR (xa hoi)). hieu ((ve cham) or (va cam)) luc van hoang di su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((ma hoi) OR (xa hoi)). hieu ((ve cham) OR (va cam)) luc van hoang di su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((ma hoi) OR (xa hoi)). hieu ((ve cham) or (va cam)) luc van hoang di su tien".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((ma hoi) OR (xa hoi)). hieu ((ve cham) or (va cam)) luc van hoang di su tien*.