Perhaps you should try some spelling variations:
mai hoi » mai khoi, dai hoi, lai hoi
han tai » hang tai, nhan tai, van tai
hieu ve » hieu va, hieu van
sach ty » sach y, sach tu, sach thu
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty xang, ty hang
cu tren » tu tren, dua tren
ma hoi » xa hoi, ma hoa, me hoi
ve cam » ve cham, ve cac, va cam
xuc va » tuc va, luc va, xac va
tai cu » tai cuc, tai cua, tai co

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 ty nang ((ma hoi) OR (mai hoi)). hieu ve cam ((xuc va) or (duc va)) han tai cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((ma hoi) OR (mai hoi)). hieu ve cam ((xuc va) OR (duc va)) han tai cu tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ((ma hoi) OR (mai hoi)). hieu ve cam ((xuc va) or (duc va)) han tai cu tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((ma hoi) OR (mai hoi)). hieu ve cam ((xuc va) or (duc va)) han tai cu tren*.