@article{oai:u-ryukyu.repo.nii.ac.jp:02007191,
 author = {平敷, 兼貴 and 屋良, 秀夫 and Heshiki, Kenki and Yara, Hideo},
 issue = {6},
 journal = {琉球大学理工学部紀要. 工学篇, Bulletin of Science & Engineering Division, University of the Ryukyus. Engineering},
 month = {Mar},
 note = {In purpose to find new sources of molding sand, survey and test were made on every accessible sands throughout the island of Okinawa. In the middle and northern districts of the island. whose considerable parts are covered with a stratum called "Kunigami gravel layer", many sands proved their good quality suitable to foundry use as green sand or silica sand. Some of them are very rich si1ica sand. having chemical analysis of over 95% of SiO_2. Most of them hold proper grain-size distribution for molding sand. and retain fair quantity for the use., 紀要論文},
 pages = {7--16},
 title = {沖縄本島の鋳物砂について(第1報)},
 year = {1973}
}