Perhaps you should try some spelling variations:
hanh khoa » hang khoa, anh khoa, hanh hoa
mach hoc » cach hoc, dich hoc, anh hoc
cuu toan » cuu hoan, cua toan, huu toan
toan hoc » toan khoa, van hoc, hoa hoc
hoc hanh » hoc nhanh, hoc thanh, hoc anh
phat dau » phan dau, pham dau, phap dau
tu mach » tu cach, tu manh, tu hach

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 toan hoc hanh khoa ((hoc xa) OR (hoc ma)) hoi va phat dau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu mach hoc tap, nghien cuu toan hoc hanh khoa ((hoc xa) OR (hoc ma)) hoi va phat dau".
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien cuu toan hoc hanh khoa ((hoc xa) OR (hoc ma)) hoi va phat dau*.