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

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) OR (va thanh)) 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) OR (va thanh)) va su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thi ((nang mai) or (lang mai)) hoi. hieu ve cham tuc ((va hanh) OR (va thanh)) 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) OR (va thanh)) va su triet*.