Sternberg, C. M. (1964). Function of the elongated narial tubes in the hooded hadrosaurs. Journal of Paleontology, 38(5), 1003-1004.
My summary: Early paper. Sternum describes the head crest anatomy, particularly in regards to where the olfactory organ is. The tubes are an extension of the narial tubes in the premaxillae (nasal passages in the upper part of the head/jaw). Because of the climate, he believes that thermoregulation was not necessary for hadrosaurs. He also notes the position of the tubes vis a vis the nasal capsule/organ does not seem to facilitate better access to incoming air, thus for that and other reasons, he concludes tubes were for underwater feeding. Note: This is an out of date hypothesis because we do not think that hadrosaurs lived or fed underwater.
Wiman, C. 1931. Parasaurolophus tubicen n. sp. aus der Kreide in New Mexico. Nova Acta Regiae Societatis Scientiarum Upsliensis, Ser. IV 7:1–11.
Note: This paper was entirely in German, so I might need to track down a translation. Summary, notes, forthcoming. From brief summaries in other papers, it appears he is arguing that the head crest resulted from / was used for sociosexual reasons/selection.
Weishampel, D. B. (1981). The nasal cavity of lambeosaurine hadrosaurids (Reptilia: Ornithischia): comparative anatomy and homologies. Journal of Paleontology, 1046-1057.
My summary/notes: Description of anatomy. I found this S-loop from the above reference figure very helpful:
Terms:
soft palate - velum
premaxilla - upper jaw, part of head
rostral - towards nose/head
caudal - towards tail
caudodorsal - near the end of the tail
ventral - underside, belly
dorsal - upperside, back
choana -An opening at the back of the nasal passage
subequal - almost but not exactly equal
diverticulum - an outpouching of a hollow (or a fluid-filled) structure in the body.
nares, narial - nostril, nasal
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