Poland: Poland, country of central Europe. It is located at a geographic crossroads that links the forested lands of northwestern Europe to the sea lanes of the Atlantic Ocean and the fertile plains of the Eurasian frontier. Poland’s capital city is Warsaw, and other important cities include Krakow and Gdansk.

: https://www.britannica.com/place/Poland

The Netherlands (Dutch: Nederland, [ˈneːdərlɑnt] ()), also commonly known as Holland, is a country located mainly in Northwestern Europe.The European portion of the Netherlands consists of twelve separate provinces that border Germany to the east, Belgium to the south, and the North Sea to the northwest, with maritime borders in the North Sea with Belgium, Germany and the United Kingdom.

: https://en.m.wikipedia.org/wiki/Netherlands

The Netherlands Tourism: TripAdvisor has 3,635,783 reviews of The Netherlands Hotels, Attractions, and Restaurants making it your best The Netherlands resource.

: https://www.tripadvisor.com/Tourism-g188553-The_Netherlands-Vacations.html

Oman: Geographical and historical treatment of Oman, including maps, statistics, and a survey of its people, economy, and government.

: https://www.britannica.com/place/Oman

The Republic of Singapore is an island country and city-state at the southern end of the Malay Peninsula in Asia.Singapore is north of the equator.Its closest neighbors are Malaysia and Indonesia.About 5.40 million people live in Singapore, of which 3.31 million are citizens, and most of them (76%) are Chinese.In Tamil, an old Indian language, “Singaporean”, from which Singapore got its name …

: https://simple.m.wikipedia.org/wiki/Singapore