Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach thieu
nang mai » nang ma, nang tai, nang cai
lang mai » lang dai, lang hai, lang man
cham tuc » nham thuc, pham thuc, tham thuc
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
tuc va » thuc va, truc va, tuc xa

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 thi ((nang mai) or (lang mai)) hoi. hieu ve cham tuc va hanh va su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thi ((nang mai) OR (lang mai)) hoi. hieu ve cham tuc va hanh va su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach thi ((nang mai) or (lang mai)) hoi. hieu ve cham tuc va hanh va su triet*.