Perhaps you should try some spelling variations:
cong thuoc » cong thuc, dong thuoc, long thuoc
nganh hoa » khanh hoa, danh hoa, ninh hoa
thanh hoa » thanh pho
sach hoc » cach hoc, sach hoi, mach hoc
cuu cong » cua cong, thu cong, cac cong
dan phan » doan phan, dan chan, van phan
phan van » pham van, thanh van, luan van
tu sach » thu sach, su sach, te sach

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 cong thuoc ((nganh hoa) OR (thanh hoa)) hoc ma hoa dan phan van~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach hoc tap, nghien cuu cong thuoc ((nganh hoa) OR (thanh hoa)) hoc ma hoa dan phan van".
• Adding a wildcard symbol may retrieve word variants: tu sach hoc tap, nghien cuu cong thuoc ((nganh hoa) OR (thanh hoa)) hoc ma hoa dan phan van*.