1. Abel R.J.R., Furino S.C.: Kirkman triple systems. In: Colburn C.J., Dinitz J.H. (eds.) The CRC Handbook of Combinatorial Designs, pp. 88–89. CRC Press, Boca Raton (1996).
2. Ahlswede R., Aydinian H.K., Khachatrian L.H.: On perfect codes and related concepts. Des. Codes Cryptogr. 22, 221–237 (2001).
3. Beutelspacher A.: On parallelisms in finite projective spaces. Geom. Dedic. 3, 35–45 (1974).
4. Beutelspacher A.: On $$t$$ -covers in finite projective spaces. Geom. Dedic. 12, 10–16 (1979).
5. Beutelspacher A., Ueberberg J.: A characteristic property of geometric $$t$$ -spreads in finite projective spaces. Eur. J. Comb. 12, 277–281 (1991).