Europe

• U.K. Commercial Releases

  • 1988 HYDROLOGY (Stumm 51), LP

    1988 HYDROLOGY AND 1 + 2 (C Stumm 51), Audio Cassette

    1988 HYDROLOGY PLUS 1 + 2 (CD Stumm 51), CD

  • 1993 HYDROLOGY AND 1 + 2 (C Stumm 51), Audio Cassette [re-edition]

    1993 HYDROLOGY PLUS 1 + 2 (CD Stumm 51), CD [re-edition]

  • 2001 HYDROLOGY PLUS 1 + 2 (CD Stumm 51), CD [re-edition]

  • 2003 HYDROLOGY PLUS 1 + 2 (CD Stumm 51), CD [re-edition]

  • 2007 HYDROLOGY PLUS 1 + 2 (CD Stumm 51), CD [re-edition]

    2007 HYDROLOGY (i Stumm 51), Download

• U.K. Promotional Releases

  • 1987 HYDROLOGY, 12" Acetate

    1987 HYDROLOGY, Promo In-House Audio Cassette

    1987 HYDROLOGY (Stumm 51), Promo LP [test pressing]

• French Promotional Releases

  • 1987 HYDROLOGY (70602), Promo Stamped LP

• German Commercial Releases

  • 1988 HYDROLOGY (INT 146.835), LP w/ Info

  • 1995 HYDROLOGY (INT 846.835), CD [re-edition]

• German Promotional Releases

  • 1987 HYDROLOGY (INT 146.835), Promo LP [test pressing]

  • 1995 HYDROLOGIE (INT 846.835), Promo In-House DAT w/ Info

• Italian Promotional Releases

  • 1987 HYDROLOGY (Stumm 51), Promo LP [test pressing]

• Russian Commercial Releases

  • 2008 HYDROLOGY PLUS 1 + 2 (CD Stumm 51), CD