SELECT "D.C." FROM table_43071 WHERE "Races" < '20' AND "Points" > '0' AND "Drivers" = 'christian vietoris' AND "Wins" = '1'
What kind of D.C. has Races smaller than 20, and Points larger than 0, and Drivers of christian vietoris, and Wins of 1?
CREATE TABLE table_43071 (
    "Year" real,
    "Drivers" text,
    "Races" real,
    "Wins" real,
    "Poles" real,
    "F.L." real,
    "Points" real,
    "D.C." text,
    "T.C." text
)