Perhaps you should try some spelling variations:
thanh ca » thanh cha, thanh cac, thanh ha
va thanh » gia thanh, ban thanh, va tinh
nam duoc » nam thuoc, da duoc, dat duoc
co sach » bo sach, cuon sach, hoc sach
duoc va » nuoc va, duc va, duoc ma
cua tre » cuu tre, cua triet, dua tren
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
va nam » van nam, ha nam, va nay
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: co sach ((y nang) or (v nang)) cao hoi. hieu va nam duoc va thanh ca ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach ((y nang) OR (v nang)) cao hoi. hieu va nam duoc va thanh ca ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach ((y nang) or (v nang)) cao hoi. hieu va nam duoc va thanh ca ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: co sach ((y nang) or (v nang)) cao hoi. hieu va nam duoc va thanh ca ((cua tre) OR (cua te))*.