[8] Drygaś, P.: 
Isotonic operations with zero element in bounded lattices. In: Soft Computing Foundations and Theoretical Aspect (K. Atanassov, O. Hryniewicz, and J. Kacprzyk,eds.), EXIT, Warszawa 2004, pp. 181-190. 
DOI 10.1007/978-3-540-72950-1_19[10] Hartwig, R.: 
How to partially order regular elements. Math. Japon. 25 (1980), 1-13. 
MR 0571255[11] Karaçal, F., Kesiciovglu, M. N.: 
A T-partial order obtained from t-norms. Kybernetika 47 (2011), 300-314. 
MR 2828579[15] Lawson, M.: 
The natural partial order on an abundant semigroup. Proc. Edinburgh Math. Soc. 30 (1987), 2, 169-186. 
MR 0892688