Professor Landman published approximately 45 educational manuals and 80 scientific articles as author or co-author.

In 1993 he completed a monumental work of 12 volumes with the (translated) title: The Transvaal Education Association: From conflict to victory 1893-1993. He followed this with 11 volumes on the Transvaal Educational leadership, including: The role of the female teacher in the development of the organised teachers' profession of Transvaal.

During 1997-1998 he researched and authored the history of Verwoerdburg with the (translated) title: Verwoerdburg: Pearl of the Highveld (1967-1995). This work consists of about 3000 pages in 13 volumes and was completed at his own expense as a tribute to the community of Centurion.

Prof Landman co-authored the history of the congregation of Lyttelton-East Dutch Reformed Church.