Perhaps you should try some spelling variations:
dieu thien » dieu khien, dieu hien, dieu kien
thien cac » hien cac, thien cau, thieu cac
cua triet » cua viet, su triet, va triet
sach thu » sach thue, sach thieu, sach tham
dinh vai » dinh van, dinh vi, dinh va
mang xa » lang xa, mang may, dang xay
sang ma » tang ma, nang ma, sang tao
va dinh » van dinh, va kinh, va tinh
cua tre » cua te, cuu tre, dua tren
vu sach » vu bach, su sach, vu khach
cac bo » bac bo, cac co
bo va » bao va, do va, so va

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 thu ((mang xa) or (sang ma)) hoi. dieu thien cac bo va dinh vai ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach thu ((mang xa) OR (sang ma)) hoi. dieu thien cac bo va dinh vai ((cua tre) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: vu sach thu ((mang xa) or (sang ma)) hoi. dieu thien cac bo va dinh vai ((cua tre) or (cua triet))*.