Perhaps you should try some spelling variations:
doanh hoa » doanh khoa, doanh hoan, danh hoa
tuan phan » toan phan, tuan pham, than phan
luan phan » luan van, luan hoan
mach hoc » cach hoc, dich hoc, anh hoc
cuu tong » cuu cong, cuu tinh, huu tung
so doanh » so danh, su doanh, hoa doanh
cua thai » ca thai, cua hai, cua tai
thai van » thi van, thanh van, thai vung
tu mach » tu cach, tu manh, tu hach
tong so » tuong so, thong so, tong son

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu mach hoc tap, nghien cuu tong so doanh hoa hoc cua thai van ((tuan phan) OR (luan phan))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu mach hoc tap, nghien cuu tong so doanh hoa hoc cua thai van ((tuan phan) OR (luan phan))".
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien cuu tong so doanh hoa hoc cua thai van ((tuan phan) OR (luan phan))*.