Perhaps you should try some spelling variations:
khoa nganh » khoi nganh, hoc nganh
cong thuoc » cong thuc, dong thuoc, cong thuong
long thuoc » luong thuoc, dong thuoc, khong thuoc
van thanh » ban thanh, van tuan
thanh van » thanh san, thanh toan, thanh phan
thu mach » thu sach, thuat mach, thu hoach
mach hoc » cach hoc, dich hoc, anh hoc
cuu toan » cuu hoan, cua toan, huu toan
hoc van » hoc dan, hoc va, hoc vat
va hoc » van hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu mach hoc tap, nghien cuu toan khoa nganh ((cong thuoc) OR (long thuoc)) va hoc van thanh van~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu mach hoc tap, nghien cuu toan khoa nganh ((cong thuoc) OR (long thuoc)) va hoc van thanh van".
• Adding a wildcard symbol may retrieve word variants: thu mach hoc tap, nghien cuu toan khoa nganh ((cong thuoc) OR (long thuoc)) va hoc van thanh van*.