Perhaps you should try some spelling variations:
pham khong » pham hong, pham thuong, pham chuong
khong hoc » khung hoc, thong hoc, khong thuoc
sach hoc » cach hoc, sach hoi, mach hoc
cuu dong » cuu cong, cuu tong, cuu long
dong hoc » dong co, dong luc
hoc pham » hoc phan, hoc phat, hoc phap
nhan dan » phan dau, gian dan, nhan tai
te sach » toc sach
hoc dai » hoc dan
khoi va » hoi va, choi va, thoi va
khi va » phi va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach hoc tap, nghien cuu dong hoc pham khong hoc dai ((khoi va) OR (khi va)) nhan dan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach hoc tap, nghien cuu dong hoc pham khong hoc dai ((khoi va) OR (khi va)) nhan dan".
• Adding a wildcard symbol may retrieve word variants: te sach hoc tap, nghien cuu dong hoc pham khong hoc dai ((khoi va) OR (khi va)) nhan dan*.