Perhaps you should try some spelling variations:
phat duc » pham duc, phan duc, phan duoc
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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 o hoi. hieu va phat duc va danh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang o hoi. hieu va phat duc va danh vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: su sach ty nang o hoi. hieu va phat duc va danh vi ((cua tre) or (cuu tre))*.