+ <topitem name="D3">
+ <notice class="alpha">λ<sub>∆</sub></notice> of
+ N.J. Rehof, M.H. Sørensen:
+ <notice class="alpha">The λ<sub>∆</sub>-calculus</notice>
+ (1994).
+ In Lecture Notes in Computer Science, 789, pp. 516–542.
+ Springer.
+ </topitem>
+
+ <topitem name="D4">
+ <notice class="alpha">λ∆</notice> of
+ S. Ronchi Della Rocca, L. Paolini:
+ <notice class="alpha">The Parametric Lambda Calculus</notice>
+ (2004).
+ Texts in Theoretical Computer Science, An EATCS Series.
+ Springer.
+ </topitem>
+
+ <topitem name="D5">
+ <notice class="alpha">λD</notice> of
+ R. Nederpelt, H. Geuvers:
+ <notice class="alpha">Type Theory and Formal Proof</notice>
+ (2014).
+ Cambridge University Press.
+ </topitem>
+
+ <topitem name="D6">
+ <notice class="alpha">Cλξ</notice> of
+ N.G. de Bruijn:
+ <notice class="alpha">A namefree lambda calculus with facilities for internal definition of expressions and segments</notice>
+ (1978).
+ TH-report 78-WSK-03.
+ Eindhoven University of Technology, Eindhoven.
+ </topitem>
+
+ <body>
+ <img logo="smile"/>
+ Moreover, the systens of the λδ family <notice class="alpha" text="are not"/> related intentionally to
+ <link to="http://umineko.wikia.com/wiki/Lambdadelta">Lady Lambdadelta</link>,
+ the Witch of Certainty of the sound novel
+ <link to="https://it.wikipedia.org/wiki/Umineko_no_naku_koro_ni">Umineko no Naku Koro ni</link>.
+ </body>
+