[1] P. Hájek: Problém obecného pojetí metody GUHA. Kybernetika 4 (1968), 6, 505-515.
[2] P. Hájek K. Bendová Z. Renc:
The GUHA method an the three valued logic. Kybernetika 7 (1971), 6, 421-435.
MR 0324940
[3] P. Hájek:
Automatic listing of important observational statements I. Kybernetika 9 (1973), 3, 187-205.
MR 0401460
[4] P. Hájek:
Automatic listing of important observational statements II. Kybernetika 9 (1973), 4, 251-271.
MR 0401461
[5] P. Hájek:
Automatic listing of important observational statements III. Kybernetika 10 (1974), 2, 95-124.
MR 0416897