Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
thuc dac » thuoc dac, thuc dan, thuc day
dac nhan » cac nhan, danh nhan, ca nhan
va triet » va trien, ve triet, cua triet
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
nhan va » nhan tai, nhan dan, nhan tao
ma hoi » mai hoi, xa hoi, ma hoa
ve nam » he nam, va nam, le nam
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: vu sach ky nang ma hoi. hieu ve nam thuc dac nhan va ((va triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang ma hoi. hieu ve nam thuc dac nhan va ((va triet) OR (va thiet)).
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang ma hoi. hieu ve nam thuc dac nhan va ((va triet) or (va thiet))*.