Perhaps you should try some spelling variations:
mang dau » hang dau, xang dau, nang dau
thu sach » tu sach, thuat sach, thuoc sach
mang dai » lang dai, mang dat, mang lai
tu cach » tu cac
tinh ve » trinh ve, tinh ven, dinh ve
va tinh » may tinh
cam tuc » cam xuc, cam tu, nam thuc
hieu ve » hieu va, hieu van
su tien » su kien, su hien, tu tieng
ve cam » ve cham, ve cac, va cam
tuc va » thuc va, truc va, tuc xa
ve su » va su

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (thu sach)) ky ((mang dai) OR (mang dau)) hoi. hieu ve cam tuc va tinh ve su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (thu sach)) ky ((mang dai) OR (mang dau)) hoi. hieu ve cam tuc va tinh ve su tien*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (thu sach)) ky ((mang dai) OR (mang dau)) hoi. hieu ve cam tuc va tinh ve su tien*".