Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
hieu van » hieu va, thien van, lieu va
danh hai » dang hai, lanh hai, manh hai
cau tren » cu tren, dau tren, ca tren
so sach » so sanh, bo sach, co sach
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
mai hoi » mai khoi, dai hoi, lai hoi
va danh » va dinh, va dan, va hanh
hai cau » hai chau, hai chu, hai hau
cam tu » cam thu, dam tu, tam tu
nam tu » nam thu, nam thuc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ly nang mai hoi. hieu van ((cam tu) or (nam tu)) va danh hai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ly nang mai hoi. hieu van ((cam tu) OR (nam tu)) va danh hai cau tren.
• Adding a wildcard symbol may retrieve word variants: so sach ly nang mai hoi. hieu van ((cam tu) or (nam tu)) va danh hai cau tren*.