Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
dua tren » dung tren
dau tren » dau tien, dat tren, dau tieng
tu sach » thu sach, su sach, te sach
mai hoi » mai khoi, dai hoi, lai hoi
qua cac » cua cac
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang

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 y nang mai hoi. hieu qua cac nuoc va hanh vi ((dua tren) or (((cuu tre) or (dau tren))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang mai hoi. hieu qua cac nuoc va hanh vi ((dua tren) OR (((cuu tre) OR (dau tren)))).
• Adding a wildcard symbol may retrieve word variants: tu sach y nang mai hoi. hieu qua cac nuoc va hanh vi ((dua tren) or (((cuu tre) or (dau tren))))*.