Report of investigations - Minnesota Geological Survey.

1-9 (1963-68); 10 (1969); no.1-10(1963-1969); no.1-10,12,14 1963-1965,1967-1970; no.11; no.11 1970; no.13 1970; 32-36 (1984-87); 37-39 (1988-91); 41 (1992); 42 (1993); 40-44 1992-1994; 44 (1994); 43 (1994); no.42; no.43 (1994); no.44 (1994); 46 (1996); 47 (1997); 48 (1997); 46-52 (1996-98); 49 (1998); no.46; no.47; no.48; no.49; no.51 1998; no.52 1998; no.54 1999; no.50 2000; no.55 2000; no.56 2000; no.56 (2001); no.57 2001; 54-59 (1999-2002); no.58 2002; no.59 2002; no.60 2002; no.61 2002; 61 (2003); no.53 2003; no.62 2004; no.63 2006; no.64 2006; 60-66 2002-08; 66 (2008); no.65 2008; 67 (2010)