Richardson - 13 Challenges - New paperback or softback - X555z

Eichhorn - big maze book 80 Challenges - New paperback or softback - X555z

Hassan - Crossword Challenge Pro - New paperback or softback - X555z

Publication - Jesus and His Challenges - New paperback or softback - X555z

Parberry - Challenges of Life and Death - New paperback or softback - X555z

Northcott - More Challenges for Morgan - New paperback or softback - X555z

101 Computing Challenges Philippe Kerampran Paperback Lulu Press

Plant - Tarquin Mathematical Challenges - New paperback or softback - X555z