Perhaps you should try some spelling variations:
dong thuoc » dung thuoc, dang thuoc, don thuoc
thu sach » tu sach, thuat sach, thuoc sach
sach hoc » cach hoc, sach hoi, mach hoc
cuu dong » cuu cong, cuu tong, cuu long
anh dong » anh huong, anh son
thuoc ma » hoc ma, duoc ma
phan van » pham van, thanh van, luan van
nhan tao » nhan tai, nhan dan
co anh » cao anh, co hanh, do anh
hoa va » hoa van, hoa xa, hoa vo

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach hoc tap, nghien cuu dong co anh dong thuoc ma hoa va ((phan van) or (nhan tao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach hoc tap, nghien cuu dong co anh dong thuoc ma hoa va ((phan van) OR (nhan tao)).
• Adding a wildcard symbol may retrieve word variants: thu sach hoc tap, nghien cuu dong co anh dong thuoc ma hoa va ((phan van) or (nhan tao))*.