Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, pham duy
nhan tai » hang tai, van tai, toan tai
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
va cham » va chat, va tham
duc van » duc va, duc tan, duc manh
han tai » hang tai, van tai, toan tai
ma hoi » mai hoi, xa hoi, ma hoa
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 hoi. lieu va cham duc van ((han tai) or (nhan tai)) va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ma hoi. lieu va cham duc van ((han tai) OR (nhan tai)) va thiet.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. lieu va cham duc van ((han tai) or (nhan tai)) va thiet*.