Perhaps you should try some spelling variations:
hoc khanh » hoc nhanh, hoc thanh, hoa khanh
mach hoc » cach hoc, dich hoc, anh hoc
hoc hanh » hoc nhanh, hoc thanh, hoc anh
van nhan » van phan, van thanh, danh nhan
nhan tao » nhan tai, nhan dan
tu mach » tu cach, tu manh, tu hach
cuu hoa » cuu khoa, cuu hoan, cau hoa
hai van » thai van, ha van, hai tan
ma hai » ta hai, va hai, xa hai

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 hoa ((hoc khanh) OR (hoc hanh)) hoa hoc ma hai van nhan tao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu mach hoc tap, nghien cuu hoa ((hoc khanh) OR (hoc hanh)) hoa hoc ma hai van nhan tao".
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien cuu hoa ((hoc khanh) OR (hoc hanh)) hoa hoc ma hai van nhan tao*.