#Apa citation no author pdf#

Instead, cite the PDF document as you would a personal communication. If the PDF is not public or even published, such as lecture notes or course documents, it won’t have a URL. If you need extra time to track down the original, you may want to ask your professor for an extension. If you can’t find a URL, try citing the source as its original version, such as a physical book or journal article. Keep in mind that specific source types may require additional information, such as volume or issue numbers for scientific journals.Īs mentioned earlier, citing a PDF in APA format requires a URL. These formulas work for PDFs as both primary and secondary sources. (Last name of author, Year of publication) In APA format, PDF in-text citations should follow this formula:

#Apa citation no author how to#

If you’re familiar with how to write a research paper, you know that you’ll also need in-text citations. In-text, however, use the standard title case. In APA reference citations, titles use the sentence case except for periodicals (newspapers, magazines, scholarly journals, etc.), so capitalize only the first word of a title, the first word after a colon, or proper nouns. Last name of author, First name initials. Journal reference: Science Advances, DOI: 10.1126/sciadv.Write with Grammarly In general, to cite a PDF in APA format, use the same formula as you would to cite a website in APA format :

I’m not completely convinced.” He says that more work is necessary to find exactly how it applies to sound moving through heavier elements. “You can use these fundamental constants to get something with units of velocity, but I can’t quite see a good fundamental reason for why it is a bound. However, Graeme Ackland at the University of Edinburgh in the UK says that it isn’t clear the calculations produce a speed limit. They also looked at experimental data for 133 materials and found that none of them broke the limit. They calculated that it should be close to the theoretical limit. The speed of sound is also dependent on the mass of the atoms in the material, so the researchers predicted that solid metallic hydrogen – a material that theoretically exists at the centre of giant planets, but for which laboratory evidence has been hotly contested – should have the highest speed of sound.

“If you change these constants by a few per cent, then the proton might not be stable anymore, and you might not even have the processes in stars resulting in the synthesis of heavy elements, so there would be no carbon, no life,” he says. Trachenko says we have a pretty good idea of these values, because if they were changed even a bit, the universe wouldn’t look at all like it does. To make this calculation, Kostya Trachenko at Queen Mary University of London and his colleagues started with two well-known physical constants: the ratio of proton mass to electron mass, and the fine structure constant, which characterises the strength of interactions between charged particles. It is about 36 kilometres per second, more than 8000 times lower than the speed of light in a vacuum. But the maximum speed of sound moving through a solid or a liquid has just been calculated for the first time. The universal speed limit of any kind of wave – be it electromagnetic or gravitational – travelling through a vacuum has been known since Albert Einstein developed his theory of special relativity in 1905. Sound waves travel through interactions between atoms, which limits their speed