Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
nhan duc » nhan duoc, nhan luc, phan duc
van tuan » van quan, van ban, anh tuan
tuan vi » quan vi, luan vi, quans vi
duc van » duc va, duc tan, duc manh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
nang ho » nang hoc, nang co, tang ho
va nhan » van nhan, ca nhan, va phan

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 ky ((nang x) or (nang ho)) hoi. hieu va nhan duc van tuan vi ((va thiet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang x) OR (nang ho)) hoi. hieu va nhan duc van tuan vi ((va thiet) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang x) or (nang ho)) hoi. hieu va nhan duc van tuan vi ((va thiet) or (su triet))*.