Perhaps you should try some spelling variations:
nhan tai » hang tai, van tai, toan tai
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
tu sach » thu sach, te sach, tu cach
ty nang » ky nang, ty xang, ty hang
su sach » so sach, vu sach
cu tren » tu tren, dua tren
ma hoi » mai hoi, xa hoi, ma hoa
va cam » va cham, va cac, va cao
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) or (su sach)) ty nang ma hoi. hieu va cam ((xuc va) or (duc va)) nhan tai cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ty nang ma hoi. hieu va cam ((xuc va) OR (duc va)) nhan tai cu tren.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ty nang ma hoi. hieu va cam ((xuc va) or (duc va)) nhan tai cu tren*.