Perhaps you should try some spelling variations:
pham duy » pham duc
van hanh » van thanh, ban hanh, van anh
hanh lai » hanh lam, hanh tai, thanh lap
cua viet » ca viet, hoa viet, cua dieu
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
duy van » duy vat, dung van
x hoi » xa hoi, o hoi, x ho

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 ty nang x hoi. hieu ve pham duy van hanh lai ((cua viet) or (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang x hoi. hieu ve pham duy van hanh lai ((cua viet) OR (cua vat)).
• Adding a wildcard symbol may retrieve word variants: su sach ty nang x hoi. hieu ve pham duy van hanh lai ((cua viet) or (cua vat))*.