Perhaps you should try some spelling variations:
sach hoc » cach hoc, sach hoi, mach hoc
cuu dong » cuu cong, cuu tong, cuu long
dong hoc » dong co, dong luc
san khoa » toan khoa, hang khoa, da khoa
khoa hoc » hoa hoc
khao cuu » cham cuu, chao chu, kho cua
phan van » pham van, thanh van, luan van
tu sach » thu sach, su sach, te sach
hoc san » hoc dan, toc san, hoc can
hoc xa » hoc ma
ho chu » hoi chu, cho chu, ho chua

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach hoc tap, nghien cuu dong hoc san khoa hoc xa ((khao cuu) or (ho chu)) phan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach hoc tap, nghien cuu dong hoc san khoa hoc xa ((khao cuu) OR (ho chu)) phan van.
• Adding a wildcard symbol may retrieve word variants: tu sach hoc tap, nghien cuu dong hoc san khoa hoc xa ((khao cuu) or (ho chu)) phan van*.