https://www.avocetta.org/articles/vol-25-2-vdn-laying-dates-clutch-size-and-breeding-success-in-the-pallid-swift-emapus-pallidusem-in-sofia-bulgaria/
Laying dates, clutch size and breeding success in the Pallid Swift Apus pallidus in Sofia, Bulgaria...
Volume 25 - N. 2 | Laying dates, clutch size and breeding success in the Pallid Swift Apus pallidus in Sofia, Bulgaria
clutch sizein thepallid swiftapus pallidussofia bulgaria
https://www.dutchavifauna.nl/record/69468
Vale Gierzwaluw - Apus pallidus | 26 oktober 2022 Bergen (NH) - Dutch Avifauna
vale gierzwaluwapus pallidusbergen nhoktoberdutch
https://balkanfauna.com/vid/apus-pallidus/
Блед бързолет (Apus pallidus) — Птици в България | FAUNA BG
Блед бързолет (Apus pallidus): 51 наблюдения в България на картата, статус IUCN „Незастрашен“.
apus pallidusfauna
https://vi.wikipedia.org/wiki/Apus_pallidus
Apus pallidus – Wikipedia tiếng Việt
apus palliduswikipedia
https://www.avocetta.org/articles/vol-15-12-buv-chick-mortality-and-hatching-asynchrony-in-the-pallidswiftinbspnbspnbsp-apus-pallidusi/
Chick mortality and hatching asynchrony in the Pallid Swift Apus pallidus – Avocetta
Volume 15 - N. 1/2 | Chick mortality and hatching asynchrony in the Pallid Swift Apus pallidus
in thepallid swiftapus palliduschickmortality