Walrecht B.J.J.R. (1961) Opmerkingen over de nestbouw en nestplaatskeuze van zwaluwen. ARDEA 49 (3-4): 164-175

The author considers details of nestbuilding with the House Martin (Delichon urbica) and the Swallow (Hirundo rustica). He compares the habits of nestbuilding with those of Petrochelidon pyrrhonata (= albifrons) especially with stress on the influences of the environment causing variety of nest shapes if the birds choose different nestsites.