Table:
text: United States House of Representatives elections, 1988
Ohio
Ohio
District Incumbent Party First_elected Result_ Candidates
Ohio 7 Mike DeWine Republican 1982 Re-elected Mike DeWine (R) 73.9% Jack Schira (D) 26.1%
Ohio 8 Buz Lukens Republican 1986 Re-elected Buz Lukens (R) 75.9% John W. Griffin (D) 24.1%
Ohio 9 Marcy Kaptur Democratic 1982 Re-elected Marcy Kaptur (D) 81.3% Al Hawkins (R) 18.7%
Ohio 12 John Kasich Republican 1982 Re-elected John Kasich (R) 80.1% Mark P. Brown (D) 19.9%
Ohio 13 Don Pease Democratic 1976 Re-elected Don Pease (D) 69.8% Dwight Brown (R) 30.2%
Ohio 14 Thomas C. Sawyer Democratic 1986 Re-elected Thomas C. Sawyer (D) 74.7% Loretta Lang (R) 25.3%
Ohio 16 Ralph Regula Republican 1972 Re-elected Ralph Regula (R) 78.6% Melvin J. Gravely (D) 21.4%

Question: Who are all the candidates who ran in the 1988 United States House of Representatives elections in the Ohio District where the incumbent is Ralph Regula?