Question: Memorial Ossuary Cer, was built in the village Tekeriš on the mountain Cer, the remains of the killed Serbian soldiers after what, which was fought between Austria-Hungary and Serbia in August 1914 during the early stages of the Serbian Campaign of the First World War?

Context paragraphs:
Pavle Jurišić Šturm: Pavle Jurišić Šturm KCMG (; August 8, 1848 – January 13, 1922) was a Serbian general most known for commanding the Serbian 3rd Army in World War I.  Born in Prussian Silesia, of ethnic Sorb (Slavic) origin, he and his brother moved to Serbia and joined the Serbian army.  Šturm was one of the most important commanders in the Serbian army in World War I, especially during its first two years, the time when his 3rd army was main support either for the 2nd army during the battle of Cer, or for the 1st army during the battle of Kolubara.

Battle of Kolubara: The Battle of Kolubara (Serbian: Колубарска битка, "Kolubarska bitka" , German: "Schlacht an der Kolubara" ) was fought between Austria-Hungary and Serbia in November and December 1914, during the Serbian Campaign of World War I.  It commenced on 16 November, when the Austro-Hungarians under the command of Oskar Potiorek reached the Kolubara River during their third invasion of Serbia that year, having captured the strategic town of Valjevo and forced the Serbian Army to undertake a series of retreats.  The Serbs withdrew from Belgrade on 29–30 November, and the city soon fell under Austro-Hungarian control.  On 2 December, the Serbian Army launched a surprise counter-attack all along the front.  Valjevo and Užice were retaken by the Serbs on 8 December and the Austro-Hungarians retreated to Belgrade, which 5th Army commander Liborius Ritter von Frank deemed to be untenable.  The Austro-Hungarians abandoned the city between 14 and 15 December and retreated back into Austria-Hungary, allowing the Serbs to retake their capital the following day.

Serbian Museum of Corfu: The Serbian Museum of Corfu (Serbian: Српска кућа/Srpska kuća ) is a museum in Corfu, Greece.  It houses rare exhibits about the Serbian soldiers' tragic fate during the First World War.  The remnants of the Serbian Army of about 150,000 soldiers together with their government in exile, found refuge and shelter in Corfu, following the collapse of the Serbian Front as a result of the Austro-Hungarian attack of the 6 October 1915.  Exhibits include photographs from the three years stay of the Serbians in Corfu, together with other exhibits such as uniforms, arms and ammunition of the Serbian army, Serbian regimental flags, religious artifacts, surgical tools and other decorations of the Kingdom of Serbia.

Serbian Blue Book: The Serbian Blue Book is a collection of 52 Serbian diplomatic documents regarding events between 29 June and 6 August 1914, a period including the aftermath of the assassination of Archduke Ferdinand (the July Crisis) and the beginning of World War I, published by the Government of the Kingdom of Serbia on 18 November 1914.  It includes correspondence between Serbian ministers and diplomats, Serbia and Russia (including royal), Austria-Hungary, and Germany.  It was published in French translation in 1914, and English translation by the British Foreign Office in "Collected Diplomatic Documents Relating to the Outbreak of the European War", and also American Association for International Conciliation, in 1915.

Battle of Cer: The Battle of Cer was fought between Austria-Hungary and Serbia in August 1914 during the early stages of the Serbian Campaign of the First World War.  It took place around Cer Mountain and several surrounding villages, as well as the town of Šabac.

Memorial Ossuary on Cer: Memorial Ossuary Cer (Serbian Cyrillic: Спомен костурница на Церу) was built in the village Tekeriš on the mountain Cer.  The remains of the killed Serbian soldiers after the Battle of Cer in the First World War were buried there.  Memorial ossuary Cer is on the list of Cultural Monuments of Exceptional Importance.

Serbian Campaign of World War I: The Serbian Campaign of World War I was fought from late July 1914, when Austria-Hungary invaded the Kingdom of Serbia at the outset of World War I, until the war's conclusion in November 1918.  The front ranged from the Danube River to southern Macedonia and back north again, and it drew in forces from almost all the combatants of the war.

Gavrilo Princip: Gavrilo Princip (Serbian Cyrillic: , ] ; 25 July [O.S. 13 July] 1894 28 April 1918) was a Bosnian Serb member of Young Bosnia, a Yugoslavist organization seeking an end to Austro-Hungarian rule in Bosnia and Herzegovina.  He assassinated Archduke Franz Ferdinand of Austria and his wife, Sophie, in Sarajevo on 28 June 1914, setting off a chain of events that would lead to outbreak of the First World War.  Princip and his accomplices were arrested and implicated the Serbian nationalist secret society known as the Black Hand, leading Austria-Hungary to issue a démarche to Serbia known as the July Ultimatum.  This was used as pretext for Austria-Hungary's invasion of Serbia, which then led to World War I.  Princip was a Yugoslav nationalist associated with the movement Mlada Bosna (Young Bosnia) which predominantly consisted of Serbs, but also Bosniaks and Croats.  During his trial he stated: "I am a Yugoslav nationalist, aiming for the unification of all Yugoslavs, and I do not care what form of state, but it must be freed from Austria."  Princip died on April 28, 1918, from tuberculosis caused by poor prison conditions that had cost him a limb earlier.

Memorial Ossuary Mačkov kamen: Memorial Ossuary Mačkov kamen (Serbian Cyrillic: ) is a memorial monument located near Ljubovija, Serbia, which stands at a height of 923 m (Mačkov kamen - Tomcat's Stone), on the mountain Jagodnja.  The remains of fallen soldiers from the First World War are stored inside.

Štip massacre: The Štip massacre was the mass murder of Serbian soldiers by Bulgarian occupational authorities in the village of Ljuboten on 15 October 1915, during World War I.  Sick and wounded Serbian soldiers, recuperating at the Štip town hospital, were detained by Bulgarian forces and IMRO militants before being taken into the vicinity of Ljuboten and killed.  An estimated 118–120 Serbian soldiers were executed in the massacre.

Supporting paragraphs: Memorial Ossuary on Cer Battle of Cer
Answer: Battle of Cer