First of all, let me answer the two crash reports of sipri and AirAsia specifically mentioned in your question (not MH370, but MH 17). Si pri(sipri.org) released SIPRI Yearbook 20 1X, and the publisher of MH 17 was DSB (Dutch Safety Committee) MH 17 report (safetyboard.nl). Here are ways to find yearbooks, reports or professional materials.

White papers published by the official websites of government departments, ministries and international organizations and their subordinate departments.

For example: Japan's 20 16 defense program-Japan's Defense Ministry (mod.go.jp).

China's White Paper on National Defense —— "Authoritative Release" column of China Ministry of National Defense (mod.gov.cn)

? Universal Declaration of Human Rights-United Nations (un.org)

Articles published by famous think tanks at home and abroad

Such as: China Institute of International Studies (ciis.org.cn), China Academy of Social Sciences (cass.cssn.cn)

? Rand Corporation (rand.org), Hoover Institution (csis.org)

National and private archives at home and abroad

Such as: National Archives of China, National Archives of the United States (NARA).

Independent third-party investigation agency

Such as: DSB in the Netherlands and NTSB in the United States.

Domestic and foreign libraries

Such as: National Library of China, Library of British Empire.

Annual reports and yearbooks issued by leading enterprises and industry associations in various industries.

Boeing and Loma Company (LMSSC)

Various professional magazines

Such as nature, science

Articles published by academic institutions

Such as: Chinese Forensic Medicine Society, american physical society.

Polling agency