Official IFOAM membersship list : : october 1988.

MLA

Official Ifoam Membersship List : October 1988. Tholey-Tholey: IFOAM, 1988.

APA

(1988). Official IFOAM membersship list : october 1988. Tholey-Tholey: IFOAM.

Chicago

Official IFOAM Membersship List: October 1988. Tholey-Tholey: IFOAM, 1988.