Perhaps you should try some spelling variations:
nhan tai » hang tai, van tai, toan tai
su sach » so sach, vu sach
va nhan » van nhan, ca nhan, va phan
ve chat » va chat, van chat
sach ky » sac ky, sach y, sach ty
ve cham » va cham, vu cham, ve chim
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
xuc va » duc va, tuc va, luc va
tai va » thai va, mai va, tri va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang ma) OR (sang ma)) hoi. hieu ((ve cham) or (ve chat)) xuc va nhan tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang ma) OR (sang ma)) hoi. hieu ((ve cham) OR (ve chat)) xuc va nhan tai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang ma) OR (sang ma)) hoi. hieu ((ve cham) or (ve chat)) xuc va nhan tai va thiet".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang ma) OR (sang ma)) hoi. hieu ((ve cham) or (ve chat)) xuc va nhan tai va thiet*.