Perhaps you should try some spelling variations:
toc tinh » toc kinh, loc tinh, doc tinh
tinh hoc » sinh hoc, tin hoc, hinh hoc
can khoa » san khoa, con khoa, van khoa
khoa hoc » hoa hoc
huu mot » cuu mot, huy mot, hieu mot
hoc can » hoc dan, hoc cao, hoc cac
van tai » von tai, van tuan
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: toc tinh hoc tap, nghien ((cuu mo) or (huu mot)) hoc can khoa hoc ma hoi va van tai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc tinh hoc tap, nghien ((cuu mo) OR (huu mot)) hoc can khoa hoc ma hoi va van tai.
• Adding a wildcard symbol may retrieve word variants: toc tinh hoc tap, nghien ((cuu mo) or (huu mot)) hoc can khoa hoc ma hoi va van tai*.