| inverse compton | IC | 141 | 9 | 2.003969 | 9912421,9912129,etc |
| proportional counter array | PCA | 43 | 7 | 1.001291 | 9912103,9912316,etc |
| signal to noise | S/N | 15 | 5 | 1.000438 | 9912027,9912351,etc |
| proportional counter unit | PCU | 20 | 5 | 1.000534 | 9912103,9912316,etc |
| wolf rayet | WR | 105 | 5 | 2.004265 | 9912203,9912276,etc |
| standard cold dark matter | SCDM | 10 | 5 | 1.000509 | 9912329,9912038,etc |
| particle mesh | PM | 316 | 5 | 2.006561 | 9912408,9912299,etc |
| intra cluster medium | ICM | 24 | 5 | 1.001118 | 9912486,9912299,etc |
| rosat all sky survey | RASS | 67 | 4 | 1.004719 | 9912362,9912125,etc |
| rayleigh jeans | RJ | 10 | 4 | 1.000296 | 9912180,9912009,etc |
| direcci'{o}n general de ense {n}anza superior e investigaci'{o}n cient'fica | DGESIC | 4 | 4 | 1.000086 | 9912160,9912162,etc |
| planetary camera | PC | 33 | 4 | 2.001114 | 9912340,9912477,etc |
| berkeley illinois maryland association | BIMA | 102 | 4 | 2.003084 | 9912009,9912010,etc |
| cool neutral medium | CNM | 29 | 3 | 2.000771 | 9912469,9912470,etc |
| space telescope imaging spectrograph | STIS | 61 | 3 | 2.002434 | 9912027,9912167,etc |
| two dimensional | 2D | 10 | 3 | 1.000589 | 9912565,9912449,etc |
| greisen zatsepin kuzmin | GZK | 8 | 3 | 1.000329 | 9912240,9912058,etc |
| tully fisher | TF | 83 | 3 | 2.001993 | 9912004,9912201,etc |
| power density spectrum | PDS | 13 | 3 | 2.000485 | 9912028,9912546,etc |
| damped ly absorber | DLA | 115 | 3 | 2.005962 | 9912352,9912268,etc |
| burst and transient source experiment | BATSE | 12 | 3 | 1.001207 | 9912019,9912351,etc |
| photodissociation region | PDR | 6 | 3 | 1.000733 | 9912197,9912369,etc |
| soft gamma ray repeater | SGR | 213 | 3 | 2.00829 | 9912446,9912207,etc |
| wide field and planetary camera 2 | WFPC2 | 34 | 3 | 2.002996 | 9912340,9912477,etc |
| synchrotron self compton | SSC | 39 | 3 | 2.002037 | 9912394,9912164,etc |
| kolmogorov smirnov | KS | 6 | 3 | 1.000238 | 9912424,9912121,etc |
| compact steep spectrum | CSS | 19 | 3 | 1.000446 | 9912070,9912282,etc |
| large velocity gradient | LVG | 14 | 3 | 2.000526 | 9912086,9912448,etc |