Perhaps you should try some spelling variations:
thuat trinh » thuat tinh, thuyet trinh, thuat trong
sach thien » sach thieu, sach tien, cach thien
phat trinh » phat trien, phat thanh, phat minh
giao tinh » giao trinh, giao thanh, giao tiep
giap tinh » diep tinh, tap tinh, phap tinh
hoc phat » hoc phan
gia tinh » gia dinh, gia linh, gia thanh
hoc sach » hoc sinh, hoc cac, hoc anh
minh te » minh ve, minh de, minh tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((( kinh te ((hoc phat) or (hoc pho)) thien ((giap tinh) OR (gia tinh)) ) or ( kinh te hoc sach thien ((giap tinh) OR (gia tinh)) ))) or ( minh te hoc ((phat trinh) or (thuat trinh)) giao tinh ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( kinh te ((hoc phat) OR (hoc pho)) thien ((giap tinh) OR (gia tinh)) ) OR ( kinh te hoc sach thien ((giap tinh) OR (gia tinh)) ))) OR ( minh te hoc ((phat trinh) OR (thuat trinh)) giao tinh ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( kinh te ((hoc phat) or (hoc pho)) thien ((giap tinh) OR (gia tinh)) ) or ( kinh te hoc sach thien ((giap tinh) OR (gia tinh)) ))) or ( minh te hoc ((phat trinh) or (thuat trinh)) giao tinh ))*".