Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
hanh vai » hanh vi, hanh va, hanh tai
tu sach » thu sach, su sach, tu cach
te sach » toc sach
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
va cham » va chat, va tham
y nang » ky nang, ly nang, v nang
xuc va » tuc va, luc va, xac va
vai va » mai va, dai va, hai va
thiet » thieu

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 (te sach)) y nang mai hoi. hieu va cham ((xuc va) or (duc va)) hanh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) y nang mai hoi. hieu va cham ((xuc va) OR (duc va)) hanh vai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) y nang mai hoi. hieu va cham ((xuc va) or (duc va)) hanh vai va thiet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) y nang mai hoi. hieu va cham ((xuc va) or (duc va)) hanh vai va thiet*.