Seri Olimpiade Matematika, Informatika, dan Astronomi Drs. Valentino Barus text Jakarta PT Lestari Kiranatama 2010 - ii, 54 hlm. : ilus. ; 21 cm. Drs. Valentino Barus Biografi Ilmuwan 925 925 VAL p 978-602-8982-13-9 20180925025835 INLIS000000000000286 Converted from MARCXML to MODS version 3.5 using MARC21slim2MODS3-5.xsl (Revision 1.106 2014/12/19)