Perhaps you should try some spelling variations:
sinh thai » dinh thi
thai cac » thoai cac, tai cac, khai cac
cac viet » cach viet, bac viet, ca viet
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
hieu ve » hieu va, hieu van
va sinh » va kinh, va tinh, vi sinh
tu can » tu ban, tu cac, thu canh
can ky » van ky, dan ky, ban ky
ve cam » ve cham, ve cac, va cam
xuc va » duc va, tuc va, luc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu can ky ((nang ma) or (sang ma)) hoi. hieu ve cam xuc va sinh thai cac viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu can ky ((nang ma) OR (sang ma)) hoi. hieu ve cam xuc va sinh thai cac viet.
• Adding a wildcard symbol may retrieve word variants: tu can ky ((nang ma) or (sang ma)) hoi. hieu ve cam xuc va sinh thai cac viet*.