Perhaps you should try some spelling variations:
nhan tai » hang tai, van tai, toan tai
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
cu tren » tu tren, dua tren
ve cam » ve cham, ve cac, va cam
xac va » tac va, ac va, bac 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) or (ty hang)) mai hoi. hieu ve cam ((xac va) or (duc va)) nhan tai cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty hang)) mai hoi. hieu ve cam ((xac va) OR (duc va)) nhan tai cu tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ty hang)) mai hoi. hieu ve cam ((xac va) or (duc va)) nhan tai cu tren*.