Perhaps you should try some spelling variations:
long thuoc » luong thuoc, dong thuoc, khong thuoc
doanh hoa » doanh khoa, doanh hoan, danh hoa
mach hoc » cach hoc, dich hoc, anh hoc
long hoc » dong hoc, long soc, duong hoc
nhan dan » phan dau, gian dan, nhan tai
su mach » su sach
va nhan » van nhan, ca nhan, va phan
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su mach hoc tap, nghien cuu ((long hoc) OR (long thuoc)) doanh hoa hoc ma hoi va nhan dan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su mach hoc tap, nghien cuu ((long hoc) OR (long thuoc)) doanh hoa hoc ma hoi va nhan dan".
• Adding a wildcard symbol may retrieve word variants: su mach hoc tap, nghien cuu ((long hoc) OR (long thuoc)) doanh hoa hoc ma hoi va nhan dan*.